Diode device, display device and method for manufacturing the same

ABSTRACT

A diode array is provided. The diode array includes a substrate and a plurality of light emitting diodes disposed on the substrate and arranged in an array, wherein each of the light emitting diodes includes a stack of functional layers comprising a first type semiconductor layer, a second type semiconductor layer, and a light emitting layer located between the first type semiconductor layer and the second type semiconductor layer, wherein at least one of the light emitting diodes includes: a first current limiting region abutting a vertically extending boundary of the second semiconductor layer; wherein, with respect to a top down view, the first current limiting region is formed about an outer edge of the light emitting diode and an outer perimeter of the first current limiting region is equal to or less than 400 micrometers (μm).

CROSS-REFERENCE TO RELATED APPLICATION

This application claims the benefit of priority to Taiwan PatentApplication No. 109117578 filed on May 27, 2020 and is a ContinuationApplication of PCT Application No. PCT/CN2019/088648 filed on May 27,2019, which claims the benefit of priority to Provisional PatentApplication Ser. No. 62/716,995 filed on Aug. 10, 2018, ProvisionalPatent Application Ser. No. 62/773,202 filed on Nov. 30, 2018, andProvisional Patent Application Ser. No. 62/824,313 filed on Mar. 27,2019. The entirety of the above-mentioned patent applications are herebyincorporated by reference herein and made a part of this specification.

TECHNICAL FIELD

The present disclosure relates to a micro light emitting diode(Micro-LED) device, a display device including the Micro-LED device, anda method for manufacturing a display device.

BACKGROUND

Micro-LED displays have advantages such as high contrast ratio, fastresponse speed, wide color gamut, low power consumption and longlifespan in comparison with traditional display technique, liquidcrystal display (LCD) and organic LED (OLED). However, there are stillsome technical challenges that have not been fully solved tocommercialize mass production, which include: (1) epitaxial chip andprocess, (2) mass transfer, and (3) inspection and repair.

(1) Epitaxial chip and process: When the size of the LED chip isreduced, its external quantum efficiency (EQE) is also reduced. The mainloss of EQE comes from a non-radiative recombination formed by thedefects and surface energy states of sidewalls or surfaces of LED,therefore reducing the efficiency of the micro LED. Thus, to reducenon-radiative recombination, so as to increase light emittingefficiency, is a key technology.

(2) Mass transfer: Transferring a huge amount of micro-LEDs onto adisplay substrate or circuit through a high-accuracy equipment is calledmass transfer technology, such as electrostatic transfer technology,micro transfer print technology, fluid assembly technology, opticaltransfer. The critical challenge that all above technologies are facingtoday is how to achieve massive transfer within reasonable time andreasonable cost.

(3) Inspection and repair: Quickly and accurately detecting andrepairing is also a bottleneck faced by micro-LED technology at currentstage.

SUMMARY

A diode array is provided according to an embodiment of the presentdisclosure. The diode array comprises a substrate and a plurality oflight emitting diodes disposed on the substrate and arranged in anarray, wherein each of the light emitting diodes includes a stack offunctional layers comprising a first type semiconductor layer, a secondtype semiconductor layer, and a light emitting layer located between thefirst type semiconductor layer and the second type semiconductor layer,wherein at least one of the light emitting diodes includes: a firstcurrent limiting region abutting a vertically extending boundary of thesecond semiconductor layer; wherein, with respect to a top down view,the first current limiting region is formed about an outer edge of thelight emitting diode and an outer perimeter of the first currentlimiting region is equal to or less than 400 micrometers (μm).

A display device is provided according to an embodiment of the presentdisclosure. The display device comprises at least one of theaforementioned diode array for providing an image light, an opticalcomponent for receiving the image light from the diode array andtransporting the image light to a viewer, and a control system forcontrolling the image light.

A method for fabricating a display device is provided according to anembodiment of the present disclosure. The method comprises providing theaforementioned diode array for providing an image light, providing anoptical component for receiving the image light radiated from the diodearray and transporting the image light to a viewer, and providing acontrol system for controlling the image light radiated from the diodearray through the microcontroller chips.

These and other objectives of the present invention will no doubt becomeobvious to those of ordinary skill in the art after reading thefollowing detailed description of the preferred embodiment that isillustrated in the various figures and drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

The drawings are used for better understanding of the present invention,but not intended to limit the scope of the present invention.

FIG. 1A schematically illustrates a top view of a traditional lightemitting diode.

FIG. 1B schematically illustrates a cross-sectional view of atraditional light emitting diode along line A-A′.

FIG. 1C schematically illustrates a cross-sectional view of atraditional light emitting diode along line B-B′.

FIG. 2A, FIG. 2Q and FIG. 2T schematically illustrate a top viewaccording to an embodiment of the present invention.

FIG. 2B, FIG. 2D, FIG. 2F, FIG. 2H, FIG. 2J, FIG. 2L, FIG. 2N, FIG. 2Rand FIG. 2U schematically illustrate a cross-sectional view along lineA-A′ according to an embodiment of the present invention.

FIG. 2C, FIG. 2E, FIG. 2G, FIG. 2I, FIG. 2K, FIG. 2M, FIG. 2O and FIG.2V schematically illustrate a cross-sectional view along line B-B′according to an embodiment of the present invention.

FIG. 2P, FIG. 2S-1, FIG. 2S-2, and FIG. 2W schematically illustrate theresults of conductivity measurement by conductive atomic forcemicroscope.

FIG. 3A schematically illustrates a top view according to an embodimentof the present invention.

FIG. 3B and FIG. 3D schematically illustrate a cross-sectional viewalong line A-A′ according to an embodiment of the present invention.

FIG. 3C and FIG. 3E schematically illustrate a cross-sectional viewalong line B-B′ according to an embodiment of the present invention.

FIG. 4A schematically illustrates a top view according to an embodimentof the present invention.

FIG. 4B and FIG. 4D schematically illustrate cross-sectional views alongline A-A′ according to an embodiment of the present invention.

FIG. 4C and FIG. 4E schematically illustrate a cross-sectional viewalong line B-B′ according to an embodiment of the present invention.

FIG. 5A schematically illustrates a top view according to an embodimentof the present invention.

FIG. 5B schematically illustrates a cross-sectional view along line A-A′according to an embodiment of the present invention.

FIG. 5C schematically illustrates a cross-sectional view along line B-B′according to an embodiment of the present invention.

FIG. 6A schematically illustrates a top view according to an embodimentof the present invention.

FIG. 6B schematically illustrates a cross-sectional view along line A-A′according to an embodiment of the present invention.

FIG. 6C schematically illustrates a cross-sectional view along line B-B′according to an embodiment of the present invention.

FIG. 7A and FIG. 7J schematically illustrate a top view according to anembodiment of the present invention.

FIG. 7B, FIG. 7D, FIG. 7F, FIG. 7H and FIG. 7K schematically illustratea cross-sectional view along line A-A′ according to an embodiment of thepresent invention.

FIG. 7C, FIG. 7E, FIG. 7G and FIG. 7I schematically illustrate across-sectional view along line B-B′ according to an embodiment of thepresent invention.

FIG. 8A schematically illustrates a top view according to an embodimentof the present invention.

FIG. 8B schematically illustrates a cross-sectional view along line A-A′according to an embodiment of the present invention.

FIG. 8C schematically illustrates a cross-sectional view along line B-B′according to an embodiment of the present invention.

FIG. 9-1 schematically illustrates a semiconductor structure.

FIG. 9-2 schematically illustrates forming a mask and defining currentlimiting area by ion implantation.

FIG. 9-3 schematically illustrates the removal of mask.

FIG. 9-4 schematically illustrates the formation of transparentelectrode, metal electrode and extension part of the metal electrode.

FIG. 9-5 schematically illustrates the formation of recesses.

FIG. 9-6 schematically illustrates connecting the light emitting diodeto a test substrate by a sacrificing layer.

FIG. 9-7 schematically illustrates the removal of growth substrate.

FIG. 9-8 schematically illustrates forming a metal electrode on thefirst type semiconductor layer.

FIG. 9-9 schematically illustrates performing electroluminescence (EL)detection of light emitting diode by test substrate and photoelectricsensor.

FIG. 9-10 schematically illustrates optionally removing defectedcomponent to a collecting substrate.

FIG. 9-11 schematically illustrates mass transfer of array of lightemitting components on a permanent substrate.

FIG. 9-12 schematically illustrates transferring light emittingcomponents on the permanent substrate to fill the vacancy.

FIG. 9-13 schematically illustrates finishing the transfer of the lightemitting component on the permanent substrate.

FIG. 9-14 schematically illustrates forming walls and transparentadhesive on the permanent substrate.

FIG. 9-15 schematically illustrates forming walls and phosphor withadhesive on the permanent substrate.

FIG. 9-16 schematically illustrates forming walls, transparent adhesiveand phosphor with adhesive on the permanent substrate.

FIG. 10-1 schematically illustrates a semiconductor structure.

FIG. 10-2 schematically illustrates the formation of recesses.

FIG. 10-3 schematically illustrates the removal of mask.

FIG. 10-4 schematically illustrates forming a current blocking area bydielectric material.

FIG. 10-5 schematically illustrates the formation of transparentelectrode, metal electrode and extension part of the metal electrode.

FIG. 10-6 schematically illustrates connecting the light emitting diodeto a test substrate by a sacrificing layer.

FIG. 10-7 schematically illustrates the removal of growth substrate.

FIG. 10-8 schematically illustrates forming a metal electrode on thefirst type semiconductor layer.

FIG. 10-9 schematically illustrates performing electroluminescence (EL)detection of light emitting diode by test substrate and photoelectricsensor.

FIG. 10-10 schematically illustrates optionally removing defectedcomponent to a collecting substrate.

FIG. 10-11 schematically illustrates mass transfer of array of lightemitting components on a permanent substrate.

FIG. 10-12 schematically illustrates transferring light emittingcomponents on the permanent substrate to fill the vacancy.

FIG. 10-13 schematically illustrates finishing the transfer of the lightemitting component on the permanent substrate.

FIG. 10-14 schematically illustrates forming walls and transparentadhesive on the permanent substrate.

FIG. 10-15 schematically illustrates forming walls and phosphor withadhesive on the permanent substrate.

FIG. 10-16 schematically illustrates forming walls, transparent adhesiveand phosphor with adhesive on the permanent substrate.

FIG. 11-1 schematically illustrates a top view of the micro lightemitting diode according to the present invention, which showsrectangular shape.

FIG. 11-2 schematically illustrates a top view of the micro lightemitting diode according to the present invention, which shows circularshape.

FIG. 11-3 schematically illustrates a top view of the micro lightemitting diode according to the present invention, which showstriangular shape.

FIG. 12 schematically illustrates performing optional mass transfer oflight emitting components after detection to a first container, andperforming fluid transfer of the micro light emitting diodes to areceiving substrate through a first solution.

FIG. 13 schematically illustrates a top view of the receiving substrate.

FIG. 14 schematically illustrates a first flow chart according to thepresent invention.

FIG. 15 schematically illustrates a second flow chart according to thepresent invention.

FIG. 16A schematically illustrates a top view according to an embodimentof the present invention.

FIG. 16B schematically illustrates a cross-sectional view along lineA-A′ according to an embodiment of the present invention.

FIG. 17A schematically illustrates a top view according to an embodimentof the present invention.

FIG. 17B schematically illustrates a cross-sectional view along lineA-A′ according to an embodiment of the present invention.

FIG. 18A schematically illustrates a top view according to an embodimentof the present invention.

FIG. 18B schematically illustrates a cross-sectional view along lineA-A′ according to an embodiment of the present invention.

FIG. 19A schematically illustrates a top view according to an embodimentof the present invention.

FIG. 19B schematically illustrates a cross-sectional view along lineA-A′ according to an embodiment of the present invention.

FIG. 20A schematically illustrates a top view according to an embodimentof the present invention.

FIG. 20B schematically illustrates a cross-sectional view along lineA-A′ according to an embodiment of the present invention.

FIG. 21A schematically illustrates a top view according to an embodimentof the present invention.

FIG. 21B schematically illustrates a cross-sectional view along lineA-A′ according to an embodiment of the present invention.

FIG. 22A schematically illustrates a top view according to an embodimentof the present invention.

FIG. 22B schematically illustrates a cross-sectional view along lineA-A′ according to an embodiment of the present invention.

FIG. 23A schematically illustrates a top view according to an embodimentof the present invention.

FIG. 23B schematically illustrates a cross-sectional view along lineA-A′ according to an embodiment of the present invention.

FIG. 24A schematically illustrates a top view according to an embodimentof the present invention.

FIG. 24B schematically illustrates a cross-sectional view along lineA-A′ according to an embodiment of the present invention.

FIG. 25A schematically illustrates a top view according to an embodimentof the present invention.

FIG. 25B schematically illustrates a cross-sectional view along lineA-A′ according to an embodiment of the present invention.

FIG. 26A schematically illustrates a top view according to an embodimentof the present invention.

FIG. 26B schematically illustrates a cross-sectional view along lineA-A′ according to an embodiment of the present invention.

FIG. 27A schematically illustrates a top view according to an embodimentof the present invention.

FIG. 27B schematically illustrates a cross-sectional view along lineA-A′ according to an embodiment of the present invention.

FIG. 28-1 schematically illustrates epitaxial growth of semiconductorstructures on a growth substrate.

FIG. 28-2 schematically illustrates forming a mask and defining currentlimiting area by ion implantation.

FIG. 28-3 schematically illustrates the removal of mask.

FIG. 28-4 schematically illustrates the formation of recesses andetching areas.

FIG. 28-5 schematically illustrates the formation of transparentelectrodes and electrodes.

FIG. 28-6 schematically illustrates connecting the light emitting diodeto a test substrate by a sacrificing layer.

FIG. 28-7 schematically illustrates removing the growth substrate bylaser.

FIG. 28-8 is the schematic diagram after the growth substrate isremoved.

FIG. 28-9 schematically illustrates performing electroluminescence (EL)detection of light emitting diode by test substrate and photoelectricsensor.

FIG. 28-10 schematically illustrates transferring to a transfersubstrate.

FIG. 28-11 schematically illustrates optionally removing defectedcomponent to a collecting substrate.

FIG. 28-12 schematically illustrates mass transfer of array of lightemitting components on a permanent substrate.

FIG. 28-13 schematically illustrates transferring light emittingcomponents on the permanent substrate to fill the vacancy.

FIG. 28-14 schematically illustrates finishing the transfer of the lightemitting component on the permanent substrate.

FIG. 28-15 schematically illustrates forming walls and transparentadhesive on the permanent substrate.

FIG. 28-16 schematically illustrates forming walls and phosphor withadhesive on the permanent substrate.

FIG. 28-17 schematically illustrates forming walls, transparent adhesiveand phosphor with adhesive on the permanent substrate.

FIG. 28-18 schematically illustrates a circuit block diagram of theflexible display.

FIG. 29 schematically illustrates the structure of traditional flip chipmicro light emitting diode.

FIG. 30 schematically illustrates the structure of micro light emittingdiode which the side length is reduced to lower than 10 micrometers.

FIG. 31 schematically illustrates the structure of flip chip micro lightemitting diode which the side length is reduced to lower than 10micrometers by ion implantation.

FIG. 32 schematically illustrates the structure including at least oneredundancy micro light emitting diode formed through ion implantationtechnique.

FIG. 33-1 schematically illustrates forming a first epitaxial layerstructure on a first epitaxial substrate.

FIG. 33-2 schematically illustrates a horizontal cross-sectional viewalong line A-A′ of first micro light emitting diodes formed throughphotolithography and etching process, and the pitch between the firstmicro light emitting diodes is P1.

FIG. 33-3 schematically illustrates a top view of FIG. 33-2.

FIG. 34-1 schematically illustrates a horizontal cross-sectional viewalong line A-A′, wherein the first ion implantation area and the firstsub-pixel area are defined by ion implantation.

FIG. 34-2 schematically illustrates a top view of FIG. 34-1.

FIG. 35-1 schematically illustrates a horizontal cross-sectional viewalong line A-A′, wherein a conductive layer is formed on the firstsub-pixel area.

FIG. 35-2 schematically illustrates a horizontal cross-sectional viewalong line A″-A′″, wherein the conductive layer is formed on the firstsub-pixel area.

FIG. 35-3 schematically illustrates a top view of FIG. 35-2.

FIG. 36-1 schematically illustrates electrically connecting the firstsub-pixel area including conductive layer and the first transparentsubstrate through bonding pads.

FIG. 36-2 schematically illustrates removing the first epitaxialsubstrate, and filling a first light-transmissive intermediate layerbetween the first transparent substrate and the first sub-pixel area.

FIG. 36-3 schematically illustrates a top view of FIG. 36-2.

FIG. 37-1 schematically illustrates forming a second epitaxial layerstructure on a second epitaxial substrate.

FIG. 37-2 schematically illustrates a horizontal cross-sectional viewalong line C-C′ of second micro light emitting diodes formed throughphotolithography and etching process, and the pitch between the secondmicro light emitting diodes is P3.

FIG. 37-3 schematically illustrates a top view of FIG. 37-2.

FIG. 38-1 schematically illustrates a horizontal cross-sectional viewalong line C-C′, wherein a first region of a second ion implantationarea, a second region of the second ion implantation area, and a secondsub-pixel area of the second micro light emitting diode are defined byion implantation.

FIG. 38-2 schematically illustrates a top view of FIG. 38-1.

FIG. 39-1 schematically illustrates a horizontal cross-sectional viewalong line C-C′, wherein a conductive layer is formed on the secondsub-pixel area.

FIG. 39-2 schematically illustrates a horizontal cross-sectional viewalong line C″-C′″, wherein a conductive layer is formed on the secondsub-pixel area.

FIG. 39-3 schematically illustrates a top view of FIG. 39-1.

FIG. 40-1 schematically illustrates electrically connecting the secondsub-pixel area including conductive layer structure and a secondtransparent substrate through bonding pads.

FIG. 40-2 schematically illustrates removing the second epitaxialsubstrate, and filling a second light-transmissive intermediate layerbetween the second transparent substrate and the second sub-pixel area.

FIG. 40-3 schematically illustrates a top view of FIG. 40-1.

FIG. 41-1 schematically illustrates forming a third epitaxial layerstructure on a third epitaxial substrate.

FIG. 41-2 schematically illustrates a horizontal cross-sectional viewalong line E-E′, wherein a third ion implantation area and a thirdsub-pixel area are defined by ion implantation.

FIG. 41-3 schematically illustrates a top view of FIG. 41-2.

FIG. 42-1 schematically illustrates a horizontal cross-sectional view ofa third micro light emitting diode along line C-C′, wherein a third ionimplantation area and a third sub-pixel area are defined by ionimplantation.

FIG. 42-2 schematically illustrates a top view of FIG. 42-1.

FIG. 43-1 schematically illustrates a horizontal cross-sectional viewalong line E-E′, wherein a conductive layer is formed on the thirdsub-pixel area.

FIG. 43-2 schematically illustrates a horizontal cross-sectional viewalong line E″-E′″.

FIG. 43-3 schematically illustrates a top view of FIG. 43-1.

FIG. 44-1 schematically illustrates electrically connecting the thirdsub-pixel area including conductive layer structure and a thirdtransparent substrate through bonding pads.

FIG. 44-2 schematically illustrates removing the third epitaxialsubstrate, and filling a third light-transmissive intermediate layerbetween the third transparent substrate and the third sub-pixel area.

FIG. 44-3 schematically illustrates a top view of FIG. 44-1.

FIG. 45-1 schematically illustrates stacking a first sub-pixelstructure, a second sub-pixel structure, and a third sub-pixel structureby light light-transmissive adhesive layers (A-1 and A-2) to form athree-dimensional stack of RGB pixels array, thereby achieving the microlight emitting diode.

FIG. 45-2 schematically illustrates an enlargement horizontalcross-sectional view of a first pixel along line G-G′.

FIG. 45-3 schematically illustrates a top view of FIG. 45-2.

FIG. 46-1 schematically illustrates a horizontal cross-sectional viewalong line H-H′ according to another embodiment of the presentinvention, wherein R1-1 is the first sub-pixel, R1-2 is the firstredundancy sub-pixel, G1-1 is the second sub-pixel, G1-2 is the secondredundancy sub-pixel, B1-1 is the third sub-pixel, and B1-2 is the thirdredundancy sub-pixel.

FIG. 46-2 schematically illustrates a top view of FIG. 46-1.

FIG. 47-1 schematically illustrates a horizontal cross-sectional viewalong line I-I′ according to another embodiment of the presentinvention, wherein R1-1 is first sub-pixel, R1-2, R1-3, R1-4, R1-5 andR1-6 are first redundancy sub-pixels, G1-1 is second sub-pixel, G1-2,G1-3 and G1-4 are second redundancy sub-pixels, B1-1 is third sub-pixel,and B1-2 is third redundancy sub-pixel.

FIG. 47-2 schematically illustrates a top view of FIG. 47-1.

FIG. 48-1 schematically illustrates a horizontal cross-sectional viewalong line J-J′ according to another embodiment of the presentinvention, wherein R-1 is first sub-pixel, R1-2, R1-3, R1-4, R1-5 andR1-6 are first redundancy sub-pixels, G1-1 is second sub-pixel, G1-2,G1-3, G1-4, G1-5 and G1-6 are second redundancy sub-pixels, B1-1 isthird sub-pixel, and B1-2, B1-3, B1-4, B1-5 and B1-6 are thirdredundancy sub-pixels.

FIG. 48-2 schematically illustrates a top view of FIG. 48-1.

FIG. 49-1 schematically illustrates a horizontal cross-sectional viewalong line K-K′ according to another embodiment of the presentinvention, wherein R1-1, R1-2, R1-3, R1-4, R1-5 and R1-6 are firstsub-pixels, G1-1, G1-2, G1-3, G1-4, G1-5 and G1-6 are second sub-pixels,and B1-1, B1-2, B1-3, B1-4, B1-5 and B1-6 are third sub-pixels.

FIG. 49-2 schematically illustrates a top view of FIG. 49-1.

FIG. 50 schematically illustrates another embodiment of the presentinvention, wherein the epitaxial substrates (S1, S2 and S3) aretransparent substrates, and the RGB micro light emitting diode may bedirectly stacked in 3D without transferring to a transparent substrate,thereby simplifying the process.

FIG. 51 schematically illustrates another embodiment of the presentinvention further including a black mattress layer to increase thecontrast of pixels.

FIG. 52 schematically illustrates another embodiment of the presentinvention further including a magnetic layer in each of the micro lightemitting diodes to increase precision of 3D stacking.

FIG. 53 schematically illustrates another embodiment of the presentinvention further including a current blocking area located at surfaceand side area of the micro light emitting diode in each of the microlight emitting diodes.

FIG. 54 schematically illustrates another embodiment of the presentinvention further including a current limiting area located at surfaceand side area of the micro light emitting diode in each of the microlight emitting diodes.

FIG. 55-1 schematically illustrates another embodiment of the presentapplication which can be applied to augmented reality (AR).

FIG. 55-2 schematically illustrates another embodiment of the presentapplication which can be applied to augmented reality (AR).

FIG. 55-3 schematically illustrates another embodiment of the presentapplication which can be applied to augmented reality (AR).

FIG. 55-4 schematically illustrates another embodiment of the presentapplication which can be applied to augmented reality (AR).

FIG. 55-5 schematically illustrates an integrated control system.

FIG. 56-1 schematically illustrates a smart glass structure.

FIG. 56-2 schematically illustrates an embodiment of the presentinvention which is applied to the smart glass structure.

FIG. 56-3 schematically illustrates an embodiment of the presentinvention which is applied to the smart glass structure.

FIG. 56-4 schematically illustrates an embodiment of the presentinvention which is applied to the smart glass structure.

FIG. 56-5 schematically illustrates an embodiment of the presentinvention which is applied to the smart glass structure.

FIG. 57-1 schematically illustrates a micro light emitting diodestructure including magnetic layer.

FIG. 57-2 schematically illustrates a lateral magnetic micro lightemitting diode structure.

FIG. 57-3 schematically illustrates a vertical magnetic micro lightemitting diode structure.

FIG. 57-4 schematically illustrates another vertical magnetic microlight emitting diode structure.

FIG. 57-5 schematically illustrates a lateral magnetic micro lightemitting diode structure, further including a first current blockinglayer.

FIG. 57-6 schematically illustrates a vertical magnetic micro lightemitting diode structure, further including a first current blockinglayer.

FIG. 57-7 schematically illustrates another vertical magnetic microlight emitting diode structure, further including a first currentblocking layer.

FIG. 57-8 schematically illustrates a lateral magnetic micro lightemitting diode structure, further including a current limiting layer.

FIG. 57-9 schematically illustrates a vertical magnetic micro lightemitting diode structure, further including a current limiting layer.

FIG. 57-10 schematically illustrates another vertical magnetic microlight emitting diode structure, further including a current limitinglayer.

FIG. 57-11 schematically illustrates a lateral magnetic micro lightemitting diode.

FIG. 57-12 schematically illustrates a lateral magnetic micro lightemitting diode.

FIG. 57-13 schematically illustrates a lateral magnetic micro lightemitting diode.

FIG. 57-14 schematically illustrates a lateral magnetic micro lightemitting diode.

FIG. 57-15 schematically illustrates a vertical magnetic micro lightemitting diode.

FIG. 57-16 schematically illustrates a vertical magnetic micro lightemitting diode.

FIG. 57-17 schematically illustrates a vertical magnetic micro lightemitting diode.

FIG. 57-18 schematically illustrates a vertical magnetic micro lightemitting diode.

FIG. 57-19 schematically illustrates mass transfer of magnetic microlight emitting diodes to a target substrate by controlling atransferring head which is magnetically attractive and controllable.

FIG. 57-20 schematically illustrates a fluid transfer system.

FIG. 57-21-1 schematically illustrates a top view of a substrate of thefluid transfer system.

FIG. 57-21-2 schematically illustrates a top view of a substrate of thefluid transfer system.

FIG. 57-22-1 schematically illustrates a top view of a substrate of thefluid transfer system.

FIG. 57-22-2 schematically illustrates a top view of a substrate of thefluid transfer system.

FIG. 57-23 schematically illustrates a fluid transfer system.

FIG. 57-24 schematically illustrates a fluid transfer system.

FIG. 57-25 schematically illustrates a fluid transfer system.

FIG. 58-1A schematically illustrates a traditional display device.

FIG. 58-2A schematically illustrates a traditional display device.

FIG. 58-3A schematically illustrates a traditional display device.

FIG. 58-1B schematically illustrates a high resolution display device.

FIG. 58-2B schematically illustrates a high resolution display device.

FIG. 58-3B schematically illustrates a high resolution display device.

FIG. 58-1C schematically illustrates a high resolution display device.

FIG. 58-2C schematically illustrates a high resolution display device.

FIG. 58-3C schematically illustrates a high resolution display device.

FIG. 59 schematically illustrates the identification requirements ofhuman eye's visual acuity.

FIG. 60A schematically illustrates a cross-section view of a lightemitting diode structure 4000 according to an embodiment.

FIG. 60B schematically illustrates a cross-section view of a lightemitting diode structure 4000′ according to an embodiment.

FIG. 60C schematically illustrates a cross-section view of a lightemitting diode structure 4000″ according to an embodiment.

FIG. 60D schematically illustrates a cross-section view of a lightemitting device according to an embodiment.

FIG. 60E-1 schematically illustrates a top view of a light emittingdevice according to an embodiment.

FIG. 60E-2 schematically illustrates a cross-section view along lineW-W′ of a light emitting diode device according to the embodiment ofFIG. 60E-1.

FIG. 60E-3 schematically illustrates an enlarged top view of a windowregion of a light emitting device according to the embodiment of FIG.60E-1.

FIG. 60F schematically illustrates cross-section view of a lightemitting diode structure 4000-F.

FIG. 60G schematically illustrates cross-section view of a lightemitting diode structure 4000-G.

FIG. 60H schematically illustrates a cross-section view of a lightemitting diode structure 4000H.

FIG. 60I schematically illustrates a cross-section view of a lightemitting diode structure 4000I.

FIG. 60J schematically illustrates a top view of a light emitting device4000J. FIG. 60K schematically illustrates a cross-section view of alight emitting device according to an embodiment.

Wherein, the numerals and symbols used in the drawings are listed asfollowing.

-   -   100: growth substrate    -   101: first type semiconductor layer    -   102: second type semiconductor layer    -   103: light emitting layer    -   104: groove    -   105: etching groove    -   101-down: bottom surface of the first type semiconductor layer;        second bottom surface    -   102-up: upper surface of the second type semiconductor layer;        second upper surface    -   201: first current limiting area, sidewall current limiting area    -   202: second current limiting area    -   203: third current limiting area    -   204: fourth current limiting area    -   205: fifth current limiting area    -   201-up: upper surface of the sidewall current limiting area,        first upper surface    -   201-down: bottom surface of sidewall current limiting area,        first bottom surface    -   201-out: outer sidewall surface of sidewall current limiting        area, first outer surface    -   201-in: inner sidewall surface of sidewall current limiting        area, first inner surface    -   202-up: upper surface of the second current limiting area    -   203-up: upper surface of the third current limiting area    -   301: transparent electrode    -   302: electrode    -   303: electrode extension part    -   304: electrode, back electrode    -   305: metal layer    -   306: metal layer, magnetic bonding layer, vacuum adsorption        layer, electrostatic adsorption layer, adhesion layer    -   307: metal layer, magnetic bonding layer, vacuum adsorption        layer, electrostatic adsorption layer, adhesion layer    -   308: metal layer, magnetic bonding layer, vacuum adsorption        layer, electrostatic adsorption layer, adhesion layer    -   309: metal layer    -   Arc: arc angle    -   D1: first depth    -   D2: second depth    -   D3: third depth    -   D4: fourth depth    -   D5: fifth depth    -   D6: sixth depth    -   D7: seventh depth    -   DS: sidewall length    -   E1: epitaxial thickness    -   F: light-transmissive adhesive    -   F1: first phosphor with adhesive    -   F2: second phosphor with adhesive    -   F3: third phosphor with adhesive    -   H1: first thickness    -   H2: second thickness    -   H3: third thickness    -   H4: fourth thickness    -   _(L-1): first low conductivity region    -   _(L-2): second low conductivity region    -   _(H): high conductivity region    -   _(L-up): upper surface low conductivity region    -   _(H-up): upper surface high conductivity region    -   _(L-cut): sidewall low conductivity region, outer surface low    -   conductivity region    -   _(H-cut): sidewall high conductivity region, outer surface high        conductivity region    -   O1: width of first aperture    -   O2: width of second aperture    -   O3: third width    -   O4: fourth width    -   O5: fifth width    -   P1: first pitch    -   P2: second pitch    -   P3: third pitch    -   RS-102-top, RS-201-top, RS-501-top: roughness of upper surface    -   RS-102-out, RS-201-out, RS-501-out: roughness of outer surface        and sidewall    -   S1: first length    -   S2: second length    -   S3: third length    -   S4: fourth length    -   T1: first width    -   T2: width    -   T3: third width    -   T4: fourth width    -   T-up: width of upper surface    -   T-down: width of bottom surface    -   T1A: first lateral width    -   T1B: second lateral width    -   T1C: third lateral width    -   U1: first surface    -   U2: second surface    -   U3: third surface    -   U4: fourth surface    -   U5: fifth surface    -   U6: sixth surface    -   400: photoelectric sensor    -   501: first current blocking area    -   502: second current blocking area    -   503: third current blocking area    -   504: fourth current blocking area    -   505: fifth current blocking area    -   506: sixth current blocking area    -   507: aperture    -   601: shielding    -   602: shielding    -   603: shielding    -   700: sacrificing layer    -   800: inspection substrate, test substrate    -   801: transfer substrate    -   805: insulating layer    -   810: collection substrate    -   820: permanent substrate    -   821: vacancy    -   830: receiving substrate    -   840: inspection substrate, test substrate    -   841: voltage source    -   831: first recess    -   832: second recess    -   833: third recess    -   850: wall structure    -   901: ion implantation    -   902: laser    -   903: laser    -   1001: first container    -   2001-L: first liquid    -   Θ1: first included angle    -   Θ2: second included angle    -   1010: flexible substrate    -   1011: micro light emitting diode    -   1012: gate driver    -   1013: source driver    -   1014: scan line    -   1015: data line    -   1100: bump    -   1101: ridge area    -   1102: N-pad    -   1103: P-pad    -   1104: P-contact layer    -   1105: multiple quantum well    -   1106: N-contact layer    -   1107: buffer layer    -   1108: ion implantation area    -   1109: redundancy micro light emitting diode    -   1110: first epitaxial substrate (S1)    -   1111: first epitaxial layer structure (Epi layer-1)    -   1112: first micro light emitting diode (M1)    -   111P1: pitch (P1)    -   111P2: pitch (P2)    -   1114: first ion implantation area (Ion-1)    -   1115: first sub-pixel area (R1)    -   1116: conductive layer (ML)    -   1117: first transparent substrate (T1)    -   1118: bonding pad (BL)    -   1119: conductive layer (ML)    -   111BR1: first light-transmissive intermediate layer (BR1)    -   1120: second epitaxial substrate (S2)    -   1121: second epitaxial layer structure (Epi layer-2)    -   1122: second micro light emitting diode (M2)    -   112P3: pitch (P3)    -   112P4: pitch (P4)    -   1124: second ion implantation area (ion-2)    -   1124-2 a: first region of the second ion implantation area        (ion-2 a)    -   1124-2 b: second region of the second ion implantation area        (ion-2 b)    -   1125: second sub-pixel area (G1)    -   1126: conductive layer (ML)    -   1127: second transparent substrate (T2)    -   1128: bonding pad (BL)    -   1129: conductive layer (ML)    -   1130: third epitaxial substrate (S3)    -   1131: third epitaxial layer structure (Epi layer-3)    -   1132: third micro light emitting diode (M3)    -   113P5: pitch (P5)    -   113P6: pitch (P6)    -   1134: third ion implantation area (Ion-3)    -   1135: third sub-pixel area (B1)    -   1136: conductive layer (ML)    -   1137: third transparent substrate (T3)    -   1138: bonding pad (BL)    -   1139: conductive layer (ML)    -   113BR3: third light-transmissive intermediate layer (BR3)    -   141, 1161, 1171, 1181, 1191, 1201, 1211, 1221, 1231, 1241, 1251:        first sub-pixel structure (Pixel 1)    -   1142, 1162, 1172, 1182, 1192, 1202, 1212, 1222, 1232, 1242,        1252: second sub-pixel structure (Pixel 2)    -   1143, 1163, 1173, 1183, 1193, 1203, 1213, 1223, 1233, 1243,        1253: third sub-pixel structure (Pixel 3)    -   1151: first light-transmissive adhesion layer (T1)    -   1152: second light-transmissive adhesion layer (T2)    -   1153: thickness (D-1)    -   1161: first sub-pixel (R1-1, R1-1A, R1-2A, R1-3, R1-4, R1-5,        R1-6)    -   1162: second sub-pixel (G1-1, G1-1A, G1-2A, G1-3A, G1-4A, G1-5A,        G1-6A)    -   1163: third sub-pixel (B1-1, B1-1A, B1-2A, B1-3A, B1-4A, B1-5A,        B1-6A)    -   1171: first redundancy sub-pixel (R1-2, R1-3, R1-4, R1-5, R1-6)    -   1172: second redundancy sub-pixel (G1-2, G1-3, G1-4, G1-5, G1-6)    -   1173: third redundancy sub-pixel (B1-2, B1-3, B1-4, B1-5, B1-6)    -   1300: black mattress layer    -   1301: magnetic layer (ML)    -   1302: current blocking area    -   1303: current limiting area    -   1400: integrated control system    -   1401: micro-LED display    -   1402: lens system    -   1403: optical component    -   1404: eye    -   1405: augmented reality (AR)    -   1500: integrated control system    -   1501: RGB micro-LED display    -   1502: lens system    -   1503: optical component    -   1504: eye    -   1505: augmented reality (AR)    -   1600: integrated control system    -   1601: micro-LED display    -   1602: lens system    -   1603: optical component    -   1604: eye    -   1605: augmented reality (AR)    -   1700: integrated control system    -   1701: RGB micro-LED display    -   1702: lens system    -   1703: optical component    -   1704: eye    -   1705: augmented reality (AR)    -   1800: integrated control system    -   1801: multi-function sensor    -   1802: microchip processors    -   1803: network interface    -   1900: integrated control system    -   1901: display    -   1902: frame    -   1903: optical component    -   1904: eye    -   1905: augmented reality (AR)    -   1906: rims    -   1907: bridge    -   2000, 2010, 2020, 2030: integrated control system    -   2001, 2011, 2021, 2031: micro-LED display    -   2002, 2012, 2022, 2032: frame    -   2003, 2013, 2023, 2033: optical component    -   2004, 2014, 2024, 2034: eye    -   2005, 2015, 2025, 2035: augmented reality (AR)    -   2006, 2016, 2026, 2036: rims    -   2007, 2017, 2027, 2037: bridge    -   3000: epitaxial substrate    -   3001: magnetic layer (ML)    -   3002: first type semiconductor layer    -   3003: light emitting layer    -   3004: second type semiconductor layer    -   3005, 3006, 3007, 3008, 3009, 3010: metal layer    -   3011, 3012: transparent conductive layer    -   3100, 3101, 3102: first current blocking layer    -   3200, 3201, 3202: first current limiting layer    -   3300: second current blocking layer    -   3400: second current limiting layer    -   3500: controllable transferring head    -   3501: electromagnetic layer    -   3502: magnetic micro light emitting diode    -   3503: substrate    -   3600: fluid transfer system    -   3601: main chamber    -   3602: solution    -   3603: substrate    -   3604: recess    -   3605: magnetic layer    -   3606: input end    -   3607: input valve    -   3608: output end    -   3609: output valve    -   3610: flow rate (F)    -   3611: first sub chamber    -   3612: second sub chamber    -   3613: third sub chamber    -   3614: magnetic micro light emitting diode with the first color    -   3615: first valve    -   3616: first input port    -   3617: magnetic micro light emitting diode with the second color    -   3618: second valve    -   3619: second input port    -   3620: magnetic micro light emitting diode with the third color    -   3621: third valve    -   3622: third input port    -   3623: fluid    -   3624: first recess with the first shape    -   3625: second recess with the second shape    -   3626: third recess with the third shape    -   3627: first sub-pixel area    -   3628: second sub-pixel area    -   3629: third sub-pixel area    -   3630: pixel area    -   3634: first recess    -   3635: second recess    -   3636: third recess    -   3637: first sub-pixel area    -   3638: second sub-pixel area    -   3639: third sub-pixel area    -   3640: pixel area    -   3650: redundancy magnetic layer    -   3651, 3661, 3671: first redundancy recess    -   3652, 3662, 3672: second redundancy recess    -   3653, 3663, 3673: third redundancy recess    -   3654, 3664, 3674: first recess    -   3655, 3665, 3675: second recess    -   3656, 3666, 3676: third recess    -   3657, 3667, 3677: first sub-pixel area    -   3658, 3668, 3678: second sub-pixel area    -   3659, 3669, 3679: third sub-pixel area    -   3660, 3670, 3680: pixel area    -   3700: fluid transfer system    -   3701: main chamber    -   3702: solution    -   3703: substrate    -   3704-1: first recess    -   3704-2: second recess    -   3704-3: third recess    -   3705: attraction layer    -   3706: input end    -   3707: input valve    -   3708: output end    -   3709: output valve    -   3710: flow rate (F)    -   3711: first sub chamber    -   3712: second sub chamber    -   3713: third sub chamber    -   3714: micro light emitting diode with the first color    -   3715: first valve    -   3716: first input port    -   3717: micro light emitting diode with the second color    -   3718: second valve    -   3719: second input port    -   3720: micro light emitting diode with the third color    -   3721: third valve    -   3722: third input port    -   3723: fluid    -   3724: first valve of substrate    -   3725: second valve of substrate    -   3726: third valve of substrate    -   3800: fluid transfer system    -   3801: main chamber    -   3802: solution    -   3803: substrate    -   3804-1: first recess    -   3804-2: second recess    -   3804-3: third recess    -   3805-1: first attraction layer    -   3805-2: second attraction layer    -   3805-3: third attraction layer    -   3806: input end    -   3807: input valve    -   3808: output end    -   3809: output valve    -   3810: flow rate (F)    -   3811: first sub chamber    -   3812: second sub chamber    -   3813: third sub chamber    -   3814: micro light emitting diode with the first color    -   3815: first valve    -   3816: first input port    -   3817: micro light emitting diode with the second color    -   3818: second valve    -   3819: second input port    -   3820: micro light emitting diode with the third color    -   3821: third valve    -   3822: third input port    -   3823: fluid    -   3900: fluid transfer system    -   3901: main chamber    -   3902: solution    -   3903: substrate    -   3904-1: first filling layer    -   3904-2: second filling layer    -   3904-3: third filling layer    -   3905-1: first attraction layer    -   3905-2: second attraction layer    -   3905-3: third attraction layer    -   3906: input end    -   3907: input valve    -   3908: output end    -   3909: output valve    -   3910: flow rate (F)    -   3911: first sub chamber    -   3912: second sub chamber    -   3913: third sub chamber    -   3914: micro light emitting diode with the first color    -   3915: first valve    -   3916: first input port    -   3917: micro light emitting diode with the second color    -   3918: second valve    -   3919: second input port    -   3920: micro light emitting diode with the third color    -   3921: third valve    -   3922: third input port    -   3923: fluid    -   3924: first valve of substrate    -   3925: second valve of substrate    -   3926: third valve of substrate    -   3927: light source

DETAILED DESCRIPTION OF DISCLOSED EMBODIMENTS

The exemplary embodiments of the present invention will be described inthe following by taking in conjunction with drawings, wherein variousdetails included in the embodiments for better understanding are merelyexemplary. Therefore, a person having ordinary skills in the art shouldrealize that various modifications and changes may be made to theembodiments described herein without departing from the scope and spiritof the invention. Also, for clarity and conciseness, descriptions ofwell-known functions and structures are omitted in the followingdescription.

FIG. 2A schematically illustrates a top view according to an embodiment.FIG. 2B, FIG. 2D, FIG. 2F, FIG. 2H, FIG. 2J, FIG. 2L, FIG. 2N, FIG. 2Rand FIG. 2U respectively illustrate a cross-sectional view along lineA-A′ in FIG. 2A according to several embodiments. In one embodiment, thediode device includes a first type semiconductor layer 101, a secondtype semiconductor layer 102, a light emitting layer 103 located betweenthe first type semiconductor layer 101 and the second type semiconductorlayer 102, and a sidewall current limiting area 201 in contact with aperiphery sidewall region of the second type semiconductor layer 102,wherein a peripheral perimeter of the sidewall current limiting area 201is equal to or less than 400 micrometers (μm).

Optionally, the diode device may further include a transparent electrode301 located above the second type semiconductor layer 102 andelectrically connected to the second type semiconductor layer 102, andthe transparent electrode 301 is partially overlapped with the sidewallcurrent limiting area 201.

A micro light emitting diode (Micro-LED) device according to anembodiment includes a first type semiconductor layer 101, a second typesemiconductor layer 102, a light emitting layer 103 located between thefirst type semiconductor layer 101 and the second type semiconductorlayer 102, a first current limiting area 201 located at a periphery ofthe second type semiconductor layer 102 and on the sidewall region ofthe second type semiconductor layer 102, and a second current limitingarea 202 surrounded by the first current limiting area 201, wherein ashortest distance between the first current limiting area 201 and thesecond current limiting area 202 is equal to or less than 50micrometers, and a periphery perimeter of the first current limitingarea 201 is equal to or less than 400 micrometers.

An upper surface U6 of the second type semiconductor layer 102, an uppersurface U1 of the first current limiting area 201, and an upper surfaceU2 of the second current limiting area 202 are coplanar, which gives thebeneficial effects such as increasing surface flatness, improvingstability of the products, and reducing non-radiative recombination,thereby improving the efficiency of micro light emitting diodes.

The first current limiting area 201 has a first depth D1, the secondcurrent limiting area 202 has a second depth D2, and the first depth D1may be equal to, greater than or less than the second depth D2.

The Micro-LED device may further include a third current limiting area203 located between the first current limiting area 201 and the secondcurrent limiting area 202, and the third current limiting area 203 is incontact with the second current limiting area 202. In such condition, anupper surface U3 of the third current limiting area 203 and the uppersurface U1 of the first current limiting area 201 are coplanar, whichhelps increasing surface flatness, improving stability of products, andreducing non-radiative recombination, thereby improving the efficiencyof micro light emitting diodes.

The first current limiting area 201 has a first depth D1, the secondcurrent limiting area 202 has a second depth D2, the third currentlimiting area 203 has a third depth D3, and the first depth D1 is equalto the second depth D2 and equal to the third depth D3. Since thesedepths are the same, they may be formed in the same ion implantationprocess, thereby simplifying the process.

Alternatively, the first current limiting area 201 has a first depth D1,the second current limiting area 202 has a second depth D2, the thirdcurrent limiting area 203 has a third depth D3, and the first depth D1is greater than the second depth D2 and greater than the third depth D3.By increasing the first depth D1 according to different epitaxialstructures, a preferable effect of reducing sidewall leakage current canbe achieved, and the light emitting efficiency (also called lightemitting efficiency) of the micro light emitting diode can be improved.

The Micro-LED device may further include a transparent electrode 301located above the second type semiconductor layer 102 and electricallyconnected to the second type semiconductor layer 102, and thetransparent electrode 301 covers the first current limiting area 201 andthe third current limiting area 203, wherein the third current limitingarea 203 is formed through ion implantation technique. Ion implantationcan increase surface flatness and stability of the products. The firstcurrent limiting area 201 has a first width T1, the second currentlimiting area 202 has a second width T202, and the third currentlimiting area 203 has a third width T203. The second width T202 isgreater than or equal to the first width T1, and the first width T1 isgreater than or equal to the third width T203.

The Micro-LED device may further include a transparent electrode 301located above the second type semiconductor layer 102 and electricallyconnected to the second type semiconductor layer 102, and thetransparent electrode 301 covers the first current limiting area 201.The transparent electrode has high light transmittance ratio, andtherefore the light emitting efficiency of the micro light emittingdiode can be improved.

The Micro-LED device may further include an electrode 302 located abovethe second type semiconductor layer 102 and electrically connected tothe transparent electrode 301, and the electrode 302 is directly incontact with the second current limiting area 202. Direct contactbetween the electrode and the semiconductor can prevent electrode frompeeling, and therefore stability of products can be improved. In suchcondition, an electrode extension part 303 located above the transparentelectrode 301 can be further included, wherein the electrode extensionpart 303 is electrically connected to the electrode 302, which helpsimproving the uniformity of current distribution and improving lightemitting efficiency of the micro light emitting diode. The Micro-LED mayfurther include a back electrode 304 located below the first typesemiconductor layer. The back electrode 304 is electrically connected tothe first type semiconductor layer. The back electrode 304 may include amulti-layer structure, which includes an ohm contact layer, a diffusionblocking layer, a connecting layer and a reflective mirror layer.

The first current limiting area 201 and the second current limiting area202 can be formed through ion implantation technique. Ion implantationcan increase sidewall flatness and stability of products; meanwhile, ionimplantation can further increase surface flatness, which can alsoimprove stability of products.

The first current limiting area 201 has a first width T1 greater than orequal to 1 micrometer.

The second current limiting area 202 may be located in the middle of thesecond type semiconductor layer 102.

Regarding the depth of the first current limiting area 201, thefollowing are some optional embodiments:

The first current limiting area 201 has a first depth D1, and the firstdepth D1 may be not greater than the depth of the second typesemiconductor layer.

Optionally, the first current limiting area 201 has a first depth D1,the first depth D1 further includes the periphery of the light emittinglayer and the first type semiconductor layer, and the first depth D1 isgreater than the summation of the depth of the second type semiconductorand the depth of the light emitting layer.

Optionally, the first current limiting area 201 has a first depth D1,the first depth D1 further includes the sidewall regions of the lightemitting layer and the first type semiconductor layer, and the firstdepth D1 is greater than the summation of the depth of the second typesemiconductor and the depth of the light emitting layer.

Optionally, the first current limiting area 201 has a first depth D1,the first depth D1 further includes the sidewall regions of the lightemitting layer and the first type semiconductor layer, and the firstdepth D1 is equal to the summation of the depth of the second typesemiconductor, the depth of the light emitting layer and the depth ofthe first type semiconductor.

Optionally, the first current limiting area 201 has a first depth D1,the first depth D1 further includes the sidewall regions of the lightemitting layer and the first type semiconductor layer, the first currentlimiting area 201 located at the sidewall region of the first typesemiconductor layer has a first lateral width T1A, the first currentlimiting area 201 located at the sidewall region of the light emittinglayer has a second lateral width T1B, and the first current limitingarea 201 located at the sidewall region of the second type semiconductorlayer has a third lateral width T1C. Wherein the first lateral width T1Ais greater than the second lateral width T1B and greater than the thirdlateral width T1C, or the third lateral width T1C is greater than thesecond lateral width T1B and greater than the first lateral width T1A.

Besides, the surface of the first current limiting area may have a firstlow conductivity region

_(L-1), and the following are some optional embodiments:

The surface of the first current limiting area has a first lowconductivity region

_(L-1), and the surface of the second type semiconductor layer has ahigh conductivity region

_(H), wherein a conductivity distribution is gradually increased fromthe first low conductivity region

_(L-1) toward the high conductivity region

_(H).

Optionally, the surface of the first current limiting area has a firstlow conductivity region

_(L-1), the surface of the second current limiting area has a second lowconductivity region

_(L-2), and the surface of the second type semiconductor layer has ahigh conductivity region

_(H), wherein a conductivity distribution is gradually increased fromboth the first low conductivity region

_(L-1) and the second low conductivity region

_(L-2) toward the high conductivity region

_(H).

Adopting the above-mentioned embodiments may facilitate reducing surfaceleakage current and sidewall leakage current and improving lightemitting efficiency of the micro light emitting diode.

Regarding the width of the first current limiting area 201, thefollowing are some optional embodiments:

The first current limiting area 201 has a first width T1, the secondcurrent limiting area 202 has a second width T202, and the second widthT202 is greater than or equal to the first width T1.

Optionally, the first current limiting area 201 has a first width T1,the second current limiting area 202 has a second width T202, and thefirst current limiting area 201 and the second current limiting area 202have a distance O3, wherein the second width T202 is greater than orequal to the first width T, and the distance O3 is greater than thesecond width T202.

By adopting the above-mentioned embodiments, the first current limitingarea 201 can reduce the sidewall leakage current and improve the lightemitting efficiency of the micro light emitting diode; the secondcurrent limiting area 202 can improve the uniformity of currentdistribution and improve the light emitting efficiency of the microlight emitting diode; and the third current limiting area 203 canimprove the uniformity of current distribution and improve the lightemitting efficiency of the micro light emitting diode, wherein theperipheral perimeter of the first current limiting area 201 is equal toor less than 400 micrometers, thereby providing various advantages ofthe micro light emitting diode.

Another Micro-LED device according to an embodiment of the presentinvention includes a first type semiconductor layer 101, a second typesemiconductor layer 102, a light emitting layer 103 located between thefirst type semiconductor layer 101 and the second type semiconductorlayer 102, a first current limiting area 201 located at a periphery ofthe second type semiconductor layer 102 and on the sidewall region ofthe second type semiconductor 102, a second current limiting area 202surrounded by the first current limiting area 201, and a third currentlimiting area 203 surrounded by the first current limiting area 201 andin contact with the second current limiting area 202, wherein a shortestdistance between the first current limiting area 201 and the secondcurrent limiting area 202 is equal to or less than 50 micrometers, and aperiphery perimeter of the first current limiting area 201 is equal toor less than 400 micrometers.

According to the above-mentioned structure, the Micro-LED has thefollowings advantages:

(1) The first current limiting area 201 can reduce sidewall leakagecurrent and improve the light emitting efficiency of the micro lightemitting diode.

(2) The second current limiting area 202 can improve the uniformity ofcurrent distribution and improve the light emitting efficiency of themicro light emitting diode.

(3) The third current limiting area 203 can improve the uniformity ofcurrent distribution and improve the light emitting efficiency of themicro light emitting diode.

(4) The peripheral perimeter is small enough to have various advantagesof the micro light emitting diode.

An upper surface U6 of the second type semiconductor layer 102, theupper surface U6 of the first current limiting area 201, an uppersurface U2 of the second current limiting area 202 and an upper surfaceU3 of the third current limiting area 203 are coplanar, which helpsincreasing surface flatness, improving stability of products andreducing non-radiative recombination, thereby improving the efficiencyof the micro light emitting diode.

The first current limiting area 201 has a first depth D1, the secondcurrent limiting area 202 has a second depth D2, and the third currentlimiting area 203 has a third depth D3, wherein the first depth D1 isequal to the second depth D2 and equal to the third depth D3. Sincethese depths are equal to each other in this embodiment, they can beformed by the same fabrication process, thereby simplifying the process.

Alternatively, the structure may be designed as that the first currentlimiting area 201 has a first depth D1, the second current limiting area202 has a second depth D2, and the third current limiting area 203 has athird depth D3, wherein the first depth D1 is greater than the seconddepth D2 and greater than the third depth D3. By increasing the firstdepth D1 according to different epitaxial structures, a preferableeffect of reducing sidewall leakage current can be achieved, and thelight emitting efficiency of the micro light emitting diode can beimproved.

The Micro-LED device may further include a transparent electrode 301located above the second type semiconductor layer 102 and electricallyconnected to the second type semiconductor layer 102, and thetransparent electrode 301 covers the first current limiting area 201 andthe third current limiting area 203. The transparent electrode has highlight transmittance ratio, thereby improving the light emittingefficiency of the micro light emitting diode. In such condition, theMicro-LED device may further include an electrode 302 located above thesecond type semiconductor layer 102 and electrically connected to thetransparent electrode 301, and the electrode 302 is directly in contactwith the second current limiting area 202, thereby preventing theelectrode from peeling and improving stability of the products. TheMicro-LED device may further include an electrode extension part 303located above the transparent electrode 301 and electrically connectedto the electrode 302.

The first current limiting area 201, the second current limiting area202 and the third current limiting area 203 may be formed through ionimplantation technique. Ion implantation can increase sidewall flatnessand improve stability of the products; meanwhile, ion implantation canfurther increase surface flatness, which can also improve stability ofthe products.

The width of the first current limiting area 201 is greater than orequal to 1 micrometer.

Besides, the second current limiting area 202 can be located in themiddle of the second type semiconductor layer 102.

Another Micro-LED device according to an embodiment of the presentinvention includes a first type semiconductor layer 101, a second typesemiconductor layer 102, a light emitting layer 103 located between thefirst type semiconductor layer 101 and the second type semiconductorlayer 102, a first current limiting area 201 located at a periphery ofthe second type semiconductor layer 102 and on the sidewall region ofthe second type semiconductor layer 102, a second current limiting area202 surrounded by the first current limiting area 201, and a thirdcurrent blocking area 503 surrounded by the first current limiting area201 and in contact with the second current limiting area 202, wherein ashortest distance between the first current limiting area 201 and thesecond current limiting area 202 is equal to or less than 50micrometers, and a periphery perimeter of the first current limitingarea 201 is equal to or less than 400 micrometers.

According to the above-mentioned structure, the Micro-LED has thefollowings advantages:

(1) The first current limiting area 201 can reduce sidewall leakagecurrent and improve the light emitting efficiency of the micro lightemitting diode.

(2) The second current limiting area 202 can improve the uniformity ofcurrent distribution and improve the light emitting efficiency of themicro light emitting diode.

(3) The third current blocking area 503 can improve the uniformity ofcurrent distribution and improve the light emitting efficiency of themicro light emitting diode.

(4) The peripheral perimeter is less than 400 micrometers, therebyhaving various advantages of the micro light emitting diode.

The upper surface U6 of the second type semiconductor layer 102, theupper surface U1 of the first current limiting area 201 and the uppersurface U2 of the second current limiting area 202 are coplanar, whichcan increase surface flatness, improve stability of the products andreduce non-radiative recombination, thereby improving the efficiency ofthe micro light emitting diode.

The first current limiting area 201 has a first depth D1, the secondcurrent limiting area 201 has a second depth D2, and the first depth D1is equal to the second depth D2. Since these depths are equal to eachother, they can be formed through the same fabrication process, therebysimplifying the process.

Optionally, the first current limiting area 201 has a first depth D1,the second current limiting area 201 has a second depth D2, and thefirst depth D1 is greater than the second depth D2.

Optionally, the first current limiting area 201 has a first depth D1,the second current limiting area 201 has a second depth D2, and thefirst depth D1 is less than the second depth D2.

By increasing or decreasing the first depth D1 according to differentepitaxial structures, a preferable effect of reducing sidewall leakagecurrent can be achieved, and the light emitting efficiency of the microlight emitting diode can be improved.

The Micro-LED device may further include a transparent electrode 301located above the second type semiconductor layer 102 and electricallyconnected to the second type semiconductor layer 102, and thetransparent electrode 301 covers the first current limiting area 201 andthe third current blocking area 503. The transparent electrode has highlight transmittance ratio, thereby improving the light emittingefficiency of the micro light emitting diode. In such condition, theMicro-LED device may further include an electrode 302 located above thesecond type semiconductor layer 102 and electrically connected to thetransparent electrode 301, and the electrode 302 is directly in contactwith the second current limiting area 202, thereby preventing theelectrode from peeling and improving stability of the products. TheMicro-LED device may further include an electrode extension part 303located above the transparent electrode 301 and electrically connectedto the electrode 302.

The first current limiting area 201 and the second current limiting area202 are formed through ion implantation technique. Ion implantation canincrease sidewall flatness and stability of products; meanwhile, ionimplantation can further increase surface flatness, which can alsoimprove stability of products.

The third current blocking area 203 may be composed of dielectricmaterial.

The width of the first current limiting area 201 may be greater than orequal to 1 micrometer.

The second current limiting area 202 may be located in the middle of thesecond type semiconductor layer 102.

Yet another Micro-LED device according to an embodiment of the presentinvention includes a first type semiconductor layer 101, a second typesemiconductor layer 102, a light emitting layer 103 disposed between thefirst type semiconductor layer 101 and the second type semiconductorlayer 102, a first current limiting area 201 located at a periphery ofthe second type semiconductor layer 102 and on the sidewall region ofthe second type semiconductor layer 102, a second current blocking area502 surrounded by the first current limiting area 201, and a thirdcurrent blocking area 503 surrounded by the first current limiting area201 and in contact with the second current blocking area 502, wherein ashortest distance between the first current limiting area 201 and thesecond current blocking area 202 is equal to or less than 50micrometers, and a periphery perimeter of the first current limitingarea 201 is equal to or less than 400 micrometers.

The structure of the Micro-LED device has the following beneficialeffects:

(1) The first current limiting area 201 can reduce sidewall leakagecurrent and improve the light emitting efficiency of the micro lightemitting diode.

(2) The second current blocking area 502 can improve the uniformity ofcurrent distribution and improve the light emitting efficiency of themicro light emitting diode.

(3) The third current blocking area 503 can improve the uniformity ofcurrent distribution and improve the light emitting efficiency of themicro light emitting diode.

(4) The peripheral perimeter is less than 400 micrometers and thereforethe size scale of the micro light emitting diode can be met, therebyhaving various advantages of the micro light emitting diode.

The upper surface U6 of the second type semiconductor layer 102 and theupper surface U1 of the first current limiting area 201 are coplanar,which helps to increase surface flatness, improve stability of theproducts and reduce non-radiative recombination, thereby improving theefficiency of the micro light emitting diode.

The Micro-LED device may further include a transparent electrode 301located above the second type semiconductor layer 102 and electricallyconnected to the second type semiconductor layer 102, and thetransparent electrode 301 covers the first current limiting area 201,the second current blocking area 502 and the third current blocking area503. In such condition, the Micro-LED device further includes anelectrode 302 located above the second type semiconductor layer 102 andelectrically connected to the transparent electrode 301, and theelectrode 302 is directly in contact with the second type semiconductorlayer 102, thereby preventing the electrode from peeling and improvingstability of the products. The transparent electrode has high lighttransmittance ratio, which can improve the light emitting efficiency ofthe micro light emitting diode. The Micro-LED device further includes anelectrode extension part 303 located above the transparent electrode 301and electrically connected to the electrode 302.

The first current limiting area 201 is formed through ion implantationtechnique. Ion implantation can increase sidewall flatness and improvestability of the products.

The second current blocking area 502 and the third current blocking area503 may be composed of dielectric material.

The width of the electrode extension part 303 may be less than the widthof the third current blocking area 503.

The width of the first current limiting area 201 may be greater than orequal to 1 micrometer.

The second current blocking area 502 may have a hollow ring shape and ahollow width O2, wherein the hollow width O2 is greater than or equal to1 micrometer.

The second current blocking area 502 may be located in the middle of thesecond type semiconductor layer 102.

Yet another Micro-LED device according to an embodiment of the presentinvention includes a first type semiconductor layer 101, a second typesemiconductor layer 102, a light emitting layer 103 located between thefirst type semiconductor layer 101 and the second type semiconductorlayer 102, a first current blocking area 501 located at a periphery ofthe second type semiconductor layer 102 and on the sidewall region ofthe second type semiconductor layer 102, a second current limiting area202 surrounded by the first current blocking area 501, and a thirdcurrent blocking area 503 surrounded by the first current blocking area501 and in contact with the second current limiting area 202, wherein ashortest distance between the first current blocking area 501 and thesecond current limiting area 202 is equal to or less than 50micrometers, and a periphery perimeter of the first current blockingarea 501 is equal to or less than 400 micrometers.

According to the structure of the Micro-LED device, the beneficialeffects can be as following:

(1) The first current blocking area 501 can reduce sidewall leakagecurrent and improve the light emitting efficiency of the micro lightemitting diode.

(2) The second current limiting area 202 can improve the uniformity ofcurrent distribution and improve the light emitting efficiency of themicro light emitting diode.

(3) The third current blocking area 503 can improve the uniformity ofcurrent distribution and improve the light emitting efficiency of themicro light emitting diode.

(4) The peripheral perimeter is less than 400 micrometers and thereforethe size scale of the micro light emitting diode can be met, therebyhaving various advantages of the micro light emitting diode.

The first current blocking area 501 may at least cover the sidewall ofthe first type semiconductor layer 101, the sidewall of the second typesemiconductor layer 102, and the sidewall of the light emitting layer103.

The Micro-LED device may further include a transparent electrode 301located above the second type semiconductor layer 102 and electricallyconnected to the second type semiconductor layer 102, and thetransparent electrode 301 covers the first current blocking area 501,the second current limiting area 202 and the third current blocking area503. The transparent electrode has high light transmittance ratio,thereby improving the light emitting efficiency of the micro lightemitting diode. In such condition, the Micro-LED device further includesan electrode 302 located above the second type semiconductor layer 102and electrically connected to the transparent electrode 301, and theelectrode 302 is directly in contact with the second current limitingarea 202, thereby preventing the electrode from peeling and improvingstability of the products. The Micro-LED device further includes anelectrode extension part 303 located above the transparent electrode 301and electrically connected to the electrode 302.

The second current limiting area 202 may be formed through ionimplantation technique. Ion implantation can increase surface flatness,thereby improving stability of the products.

The first current blocking area 501 and the third current blocking area503 may be composed of dielectric material.

The width of the electrode extension part 303 may be less than the widthof the third current blocking area 503.

The width of the first current blocking area 501 may be greater than orequal to 1 micrometer.

The second current limiting area 202 may be located in the middle of thesecond type semiconductor layer 102.

Yet another Micro-LED device according to an embodiment of the presentinvention includes a first type semiconductor layer 101, a second typesemiconductor layer 102, a light emitting layer 103 located between thefirst type semiconductor layer 101 and the second type semiconductorlayer 102, a first current blocking area 501 located at a periphery ofthe second type semiconductor layer 102 and on the sidewall region ofthe second type semiconductor layer 102, a second current limiting area202 surrounded by the first current blocking area 501, and a thirdcurrent limiting area 203 surrounded by the first current blocking area501 and in contact with the second current limiting area 202, wherein ashortest distance between the first current blocking area 501 and thesecond current limiting area 202 is equal to or less than 50micrometers, and a peripheral perimeter of the first current blockingarea 501 is equal to or less than 400 micrometers.

According to the structure of the Micro-LED device, the beneficialeffects can be as following:

(1) The first current blocking area 501 can reduce sidewall leakagecurrent and improve the light emitting efficiency of the micro lightemitting diode.

(2) The second current limiting area 202 can improve the uniformity ofcurrent distribution and improve the light emitting efficiency of themicro light emitting diode.

(3) The third current limiting area 203 can improve the uniformity ofcurrent distribution and improve the light emitting efficiency of themicro light emitting diode.

(4) The peripheral perimeter is less than 400 micrometers and thereforethe size scale of the micro light emitting diode can be met, therebyhaving various advantages of the micro light emitting diode.

The first current blocking area 501 at least covers the sidewall of thefirst type semiconductor layer 101, the sidewall of the second typesemiconductor layer 102 and the sidewall of the light emitting layer103.

The Micro-LED device may further include a transparent electrode 301located above the second type semiconductor layer 102 and electricallyconnected to the second type semiconductor layer 102, and thetransparent electrode 301 covers the first current blocking area 501 andthe third current limiting area 203. In such condition, the Micro-LEDdevice may further include an electrode 302 located above the secondtype semiconductor layer 102 and electrically connected to thetransparent electrode 301, and the electrode 302 is directly in contactwith the second current limiting area 202, thereby preventing theelectrode from peeling and improving stability of the products. Thetransparent electrode has high light transmittance ratio, and thereforethe light emitting efficiency of the micro light emitting diode can beimproved. The Micro-LED device may further include an electrodeextension part 303 located above the transparent electrode 301 andelectrically connected to the electrode 302.

The second current limiting area 202 and the third current limiting area203 are formed through ion implantation technique. Ion implantation canincrease sidewall flatness and stability of products. Ion implantationcan further increase surface flatness, which can also improve stabilityof products.

The first current blocking area 501 may be composed of dielectricmaterial.

The width of the first current blocking area 501 is greater than orequal to 1 micrometer.

The second current limiting area 202 may be located in the middle of thesecond type semiconductor layer 102.

The second current limiting area 202 has a second depth D2, the thirdcurrent limiting area 203 has a third depth D3, and the second depth D2may be equal to the third depth D3.

The second current limiting area 202 may be located in the middle of thesecond type semiconductor layer 102.

The first current blocking area 501 covering the sidewall region has athickness H1, and the first current blocking area 501 covering the uppersurface region has a thickness H2, wherein the thickness H1 may begreater than, less than or equal to the thickness H2. The first currentblocking area 501 may expose a transparent electrode that is positionedabove the second type semiconductor layer 102 and electrically connectedto the second type semiconductor layer 102.

Yet another Micro-LED device according to an embodiment of the presentinvention includes a first type semiconductor layer 101, a second typesemiconductor layer 102, a light emitting layer 103 located between thefirst type semiconductor layer 101 and the second type semiconductorlayer 102, a first current blocking area 501 located at a periphery ofthe second type semiconductor layer 102 and on the sidewall region ofthe second type semiconductor layer 102, a second current blocking area502 surrounded by the first current blocking area 501, and a thirdcurrent blocking area 503 surrounded by the first current blocking area501 and in contact with the second current blocking area 502, wherein ashortest distance between the first current blocking area 501 and thesecond current blocking area 502 is equal to or less than 50micrometers, and a peripheral perimeter of the first current blockingarea 501 is equal to or less than 400 micrometers.

According to the above-mentioned structure of the Micro-LED device, thebeneficial effects can be as following:

(1) The first current blocking area 501 can reduce sidewall leakagecurrent and improve the light emitting efficiency of the micro lightemitting diode.

(2) The second current blocking area 502 can improve the uniformity ofcurrent distribution and improve the light emitting efficiency of themicro light emitting diode.

(3) The third current blocking area 503 can improve the uniformity ofcurrent distribution and improve the light emitting efficiency of themicro light emitting diode.

(4) The peripheral perimeter is less than 400 micrometers and thereforethe size scale of the micro light emitting diode cab be met, therebyhaving various advantages of the micro light emitting diode.

The first current blocking area 501 may at least cover the sidewall ofthe first type semiconductor layer 101, the sidewall of the second typesemiconductor layer 102 and the sidewall of the light emitting layer103.

The Micro-LED device may further include a transparent electrode 301located above the second type semiconductor layer 102 and electricallyconnected to the second type semiconductor layer 102, and thetransparent electrode 301 covers the first current blocking area 501,the second current blocking area 502 and the third current blocking area503. In such condition, an electrode 302 may be further included. Theelectrode 302 is located above the second type semiconductor layer 102and electrically connected to the transparent electrode 301, and theelectrode 302 is directly in contact with the second type semiconductorlayer 102, thereby preventing the electrode from peeling and improvingstability of the products. The transparent electrode has high lighttransmittance ratio, thereby improving the light emitting efficiency ofthe micro light emitting diode. An electrode extension part 303 may befurther included. The electrode extension part 303 is located above thetransparent electrode 301 and electrically connected to the electrode302, wherein the width of the electrode extension part 303 is less thanthe width of the third current blocking area 503.

The first current blocking area 501, the second current blocking area502 and the third current blocking area 503 may be composed ofdielectric material.

The width of the first current blocking area 501 is greater than orequal to 1 micrometer.

The second current blocking area 502 may have a hollow ring shape and ahollow width O2, wherein the hollow width O2 is greater than or equal to1 micrometer.

The second current blocking area 502 may be located in the middle of thesecond type semiconductor layer 102.

Yet another Micro-LED device according to an embodiment of the presentinvention includes a first type semiconductor layer 101, a second typesemiconductor layer 102, a light emitting layer 103 located between thefirst type semiconductor layer 101 and the second type semiconductorlayer 102, a first current blocking area 501 located at a periphery ofthe second type semiconductor layer 102 and on the sidewall region ofthe second type semiconductor layer 102, a second current blocking area502 surrounded by the first current blocking area 501, and a thirdcurrent limiting area 203 surrounded by the first current blocking area501 and in contact with the second current blocking area 502, wherein ashortest distance between the first current blocking area 501 and thesecond current blocking area 502 is equal to or less than 50micrometers, and a peripheral perimeter of the first current blockingarea 501 is equal to or less than 400 micrometers.

The structure of the Micro-LED device has the following beneficialeffects:

(1) The first current blocking area 501 can reduce sidewall leakagecurrent and improve the light emitting efficiency of the micro lightemitting diode.

(2) The second current blocking area 502 can improve the uniformity ofcurrent distribution and improve the light emitting efficiency of themicro light emitting diode.

(3) The third current limiting area 203 can improve the uniformity ofcurrent distribution and improve the light emitting efficiency of themicro light emitting diode.

(4) The peripheral perimeter is less than 400 micrometers, therebyhaving various advantages of the micro light emitting diode.

The first current blocking area 501 at least covers the sidewall of thefirst type semiconductor layer 101, the sidewall of the second typesemiconductor layer 102 and the sidewall of the light emitting layer103.

The Micro-LED device further includes a transparent electrode 301located above the second type semiconductor layer 102 and electricallyconnected to the second type semiconductor layer 102, and thetransparent electrode 301 covers the first current blocking area 501,the second current blocking area 502 and the third current limiting area203. In such condition, an electrode 302 is further included, which islocated above the second type semiconductor layer 102 and electricallyconnected to the transparent electrode 301, and the electrode 302 isdirectly in contact with the second type semiconductor layer 102,thereby preventing the electrode from peeling and improving stability ofthe products. The transparent electrode has high light transmittanceratio, thereby improving the light emitting efficiency of the microlight emitting diode. An electrode extension part 303 is furtherincluded, which is located above the transparent electrode 301 andelectrically connected to the electrode 302. The first current blockingarea 501, the second current blocking area 502 and the third currentblocking area 503 are composed of dielectric material such as siliconoxide (SiO₂), silicon nitride (Si₃N₄), aluminum oxide (Al₂O₃), yttriumoxide (Y₂O₃), titanium oxide (TiO₂), hafnium oxide (HfO₂), zirconiumoxide (ZrO₂), barium zirconate (BaZrO₃), barium titanate (BaTiO₃),tantalum pentoxide (Ta₂O₅) and Silica.

The first current blocking area 501 and the third current blocking area503 are composed of dielectric material.

The third current limiting area 203 is formed through ion implantationtechnique. Ion implantation can increase surface flatness and improvestability of the products.

The width of the first current blocking area 501 is greater than orequal to 1 micrometer.

The second current blocking area 502 may have a hollow ring shape and ahollow width O2, wherein the hollow width O2 is greater than or equal to1 micrometer.

The second current blocking area 502 is located in the middle of thesecond type semiconductor layer 102.

A Micro-LED device includes a first type semiconductor layer 101, asecond type semiconductor layer 102, a light emitting layer 103 locatedbetween the first type semiconductor layer 101 and the second typesemiconductor layer 102, a first current blocking area 501 located at aperiphery of the second type semiconductor layer 102 and on the sidewallregion of the second type semiconductor layer 102, and a second currentblocking area 502 surrounded by the first current blocking area 501,wherein a shortest distance between the first current blocking area 501and the second current blocking area 502 is equal to or less than 50micrometers, and a peripheral perimeter of the first current blockingarea 501 is equal to or less than 400 micrometers.

The beneficial effects are:

(1) The first current blocking area 501 can reduce sidewall leakagecurrent and improve the light emitting efficiency of the micro lightemitting diode.

(2) The second current blocking area 502 can improve the uniformity ofcurrent distribution and improve the light emitting efficiency of themicro light emitting diode.

(3) The peripheral perimeter is less than 400 micrometers and thereforethe size scale of the micro light emitting diode can be met, therebyhaving various advantages of the micro light emitting diode.

The first current blocking area 501 at least covers the sidewall of thefirst type semiconductor layer 101, the sidewall of the second typesemiconductor layer 102 and the sidewall of the light emitting layer103.

The Micro-LED device may further include a transparent electrode 301located above the second type semiconductor layer 102 and electricallyconnected to the second type semiconductor layer 102, and thetransparent electrode 301 covers the first current blocking area 501 andthe second current blocking area 502. In such condition, an electrode302 may be further included, which is located above the second typesemiconductor layer 102 and electrically connected to the transparentelectrode 301, and the electrode 302 is directly in contact with thesecond type semiconductor layer 102, thereby preventing the electrodefrom peeling and improving the stability of the products. Thetransparent electrode has high light transmittance ratio, therebyimproving the light emitting efficiency of the micro light emittingdiode. An electrode extension part 303 may be further included, which islocated above the transparent electrode 301 and electrically connectedto the electrode 302. The first current blocking area 501 covering thesidewall region has a first thickness H1, the first current blockingarea 501 covering the upper surface region has a second thickness H2,the second current blocking area 502 has a third thickness H3, and thethird current blocking area 503 has a fourth thickness H4, wherein thefirst thickness H1 is greater than or equal to the second thickness H2,greater than or equal to the third thickness H3, and greater than orequal to the fourth thickness H4. Alternatively, the first currentblocking area 501 covering the sidewall region has a first thickness H1,the first current blocking area 501 covering the upper surface regionhas a second thickness H2, the second current blocking area 502 has athird thickness H3, and the third current blocking area 503 has a fourththickness H4, wherein the first thickness H1 is less than or equal tothe second thickness H2, less than or equal to the third thickness H3,and less than or equal to the fourth thickness H4.

The Micro-LED device may further include a third current blocking area503 surrounded by the first current blocking area 501 and in contactwith the second current blocking area 502. The third current blockingarea 503 can improve the uniformity of current distribution, therebyimproving the light emitting efficiency of the micro light emittingdiode. In such condition, the micro light emitting diode may furtherinclude a transparent electrode 301 located above the second typesemiconductor layer 102 and electrically connected to the second typesemiconductor layer 102, and the transparent electrode 301 covers thefirst current blocking area 501, the second current blocking area 502and the third current blocking area 503. An electrode 302 may further beincluded, which is located above the second type semiconductor layer 102and electrically connected to the transparent electrode 301, and theelectrode 302 is directly in contact with the second type semiconductorlayer 102. An electrode extension part 303 may be further included,which is located above the transparent electrode 301 and electricallyconnected to the electrode 302, wherein the width of the electrodeextension part 303 is less than the width of the third current blockingarea 503.

The first current blocking area 501, the second current blocking area502 and the third current blocking area 503 may be composed ofdielectric material.

The width of the first current blocking area 501 may be greater than orequal to 1 micrometer.

The second current blocking area 502 may have a hollow ring shape and ahollow width O2, wherein the hollow width O2 is greater than or equal to1 micrometer.

The second current blocking area 502 may be located in the middle of thesecond type semiconductor layer 102.

The first current blocking area 501 covering the sidewall region has afirst thickness H1, and the first current blocking area 501 covering theupper surface region has a second thickness H2, wherein the firstthickness H1 is greater than or equal to the second thickness H2.Optionally, the first current blocking area 501 covering the sidewallregion has a first thickness H1, and the first current blocking area 501covering the upper surface region has a second thickness H2, wherein thefirst thickness H1 is less than the second thickness H2.

The first current blocking area 501 covering the sidewall region has afirst thickness H1, the first current blocking area 501 covering theupper surface region has a second thickness H2, and the second currentblocking area 502 has a third thickness H3, wherein the first thicknessH1 is greater than or equal to the second thickness H2 and greater thanor equal to the third thickness H3. Alternatively, the first currentblocking area 501 covering the sidewall region has a first thickness H1,the first current blocking area 501 covering the upper surface regionhas a second thickness H2, and the second current blocking area 502 hasa third thickness H3, wherein the first thickness H1 is less than thesecond thickness H2 and less than the third thickness H3.

The first current blocking area 501 exposes a transparent electrode 301which is located above the second type semiconductor layer 102 andelectrically connected to the second type semiconductor layer 102. Thesecond current blocking area 502 exposes an electrode 302 which islocated above the second type semiconductor layer 102 and electricallyconnected to the transparent electrode 301, and the electrode 302 isdirectly in contact with the second current limiting area 202.Alternatively, the second current blocking area 502 exposes an electrode302 which is located above the second type semiconductor layer 102 andelectrically connected to the second type semiconductor layer 102.

The light emitting efficiency of the above-mentioned micro lightemitting diode is greater than 250 lumens per watt (lm/W).

The reveal ability to red, R9, of the color rendering index (CRI) of theabove-mentioned micro light emitting diode is greater than 90.

The CRI of the above-mentioned micro light emitting diode is greaterthan 90.

The general CRI Ra of the above-mentioned micro light emitting diode isgreater than 90.

A further Micro-LED device according to an embodiment of the presentinvention includes a first type semiconductor layer 101, a second typesemiconductor layer 102, a light emitting layer 103 located between thefirst type semiconductor layer 101 and the second type semiconductorlayer 102, and a sidewall current limiting area 201 directly in contactwith the periphery sidewall regions of the second type semiconductorlayer 102, the light emitting layer 103 and the first type semiconductorlayer 102, wherein the sidewall current limiting area 201 furtherincludes an upper surface 201-up, a bottom surface 101-down, an outersurface 201-out, and an inner surface 201-in. The upper surface 201-upof the sidewall current limiting area 201 and the upper surface 102-upof the second type semiconductor layer 102 are coplanar, and the outmostperiphery perimeter of the vertical projection of the first currentlimiting area 201 is equal to or less than 400 micrometers.

The beneficial effects of the Micro-LED device is as following:

(1) The sidewall current limiting area 201 can reduce sidewall leakagecurrent and improve the light emitting efficiency of the micro lightemitting diode.

(2) The peripheral perimeter is less than 400 micrometers, which meetsthe size scale of the micro light emitting diode, thereby having variousadvantages of the micro light emitting diode.

The bottom surface 201-down of the sidewall current limiting area 201and the bottom surface 101-down of the first type semiconductor layer101 are coplanar.

The vertical projection of the upper surface 201-up of the sidewallcurrent limiting area 201 has an upper surface width T-up, the verticalprojection of the bottom surface 201-down of the sidewall currentlimiting area 201 has a bottom surface width T-down, and the uppersurface width T-up is greater than the bottom surface width T-down.Alternatively, the vertical projection of the upper surface 201-up ofthe sidewall current limiting area 201 has an upper surface width T-up,the vertical projection of the bottom surface 201-down of the sidewallcurrent limiting area 201 has a bottom surface width T-down, and theupper surface width T-up is less than the bottom surface width T-down.

The vertical projection of the upper surface 201-up of the sidewallcurrent limiting area 201 may be partially overlapped with the verticalprojection of the bottom surface 201-down of the sidewall currentlimiting area 201.

The outer surface 201-out of the sidewall current limiting area 201 hasa sidewall length DS, the inner surface 201-in of the sidewall currentlimiting area 201 has a first depth D1, wherein the sidewall length DSis equal to the first depth D1. Alternatively, the outer surface 201-outof the sidewall current limiting area 201 has a sidewall length DS, theinner surface 201-in of the sidewall current limiting area 201 has afirst depth D1, wherein the sidewall length DS is greater than the firstdepth D1.

The upper surface 201-up of the sidewall current limiting area 201 andthe outer surface 201-out of the sidewall current limiting area 201 havea first included angle Θ1, the upper surface 201-up of the sidewallcurrent limiting area 201 and the inner surface 201-in of the sidewallcurrent limiting area 201 have a second included angle Θ2, wherein thefirst included angle Θ1 and the second included angle Θ2 are right angle(90°) or close to right angle, obtuse angle (greater than 90°), or acuteangle (less than 90°) respectively.

The sidewall current limiting area 201 located at the sidewall region ofthe first type semiconductor layer has a first lateral width T1A, thesidewall current limiting area 201 located at the sidewall region of thelight emitting layer has a second lateral width T1B, and the sidewallcurrent limiting area 201 located at the sidewall region of the secondtype semiconductor layer has a third lateral width T1C. In this case,the vertical projection of the first lateral width T1A is partiallyoverlapped with the vertical projections of the second lateral width T1Band the third lateral width T1C, wherein the width of the verticalprojection of the first lateral width TA is greater than the width ofthe vertical projection of the third lateral width T1C. Alternatively,the width of the vertical projection of the first lateral width T1A isless than the width of the vertical projection of the third lateralwidth T1C. Alternatively, the width of the vertical projection of thefirst lateral width T1A is equal to the width of the vertical projectionof the third lateral width T1C.

In the above-mentioned displays, a preferable effect of reducingsidewall leakage current can be achieved by controlling the depth of thesidewall current limiting area, and therefore the light emittingefficiency of the micro light emitting diode can be improved.

The Micro-LED device may further include a second current limiting area202 which is surrounded by the sidewall current limiting area, whereinthe shortest distance between the sidewall current limiting area 201 andthe second current limiting area 202 is equal to or less than 50micrometers. The second current limiting area 202 can improve theuniformity of current distribution, and the light emitting efficiency ofthe micro light emitting diode can be improved. The upper surface 102-upof the second type semiconductor layer 102, the upper surface 201-up ofthe sidewall current limiting area 201 and the upper surface 202-up ofthe second current limiting area 202 are coplanar. In this case, theMicro-LED device may further include a third current limiting area 203which is located between the sidewall current limiting area 201 and thesecond current limiting area 202 and in contact with the second currentlimiting area 202. The upper surface 203-up of the third currentlimiting area 203 and the upper surface 201-up of the sidewall currentlimiting area 201 are coplanar. The second current limiting area 202 hasa second depth D2, the third current limiting area 203 has a third depthD3, and the second depth D2 is equal to the third depth D3. TheMicro-LED device may further include a transparent electrode 301 whichis located above the second type semiconductor layer 102 andelectrically connected to the second type semiconductor layer 102, andthe transparent electrode 301 covers the upper surface 201-up of thesidewall current limiting area 201 and the upper surface 203-up of thethird current limiting area 203. In such case, the Micro-LED device mayfurther include an electrode 302 which is located above the second typesemiconductor layer 102 and electrically connected to the transparentelectrode 301, and the electrode 302 is directly in contact with thesecond current limiting area 202. The Micro-LED device may furtherinclude an electrode extension part 303 located above the transparentelectrode 301 and electrically connected to the electrode 302. Thesecond current limiting area 202 may be located in the middle of thesecond type semiconductor layer 102.

The Micro-LED device may further include a transparent electrode 301which is located above the second type semiconductor layer 102 andelectrically connected to the second type semiconductor layer 102, andthe transparent electrode 301 covers the upper surface 201-up of thesidewall current limiting area 201. In such case, the Micro-LED devicemay further include an electrode 302 located above the second typesemiconductor layer 102 and electrically connected to the transparentelectrode 301, and the electrode 302 is directly in contact with thesecond current limiting area 202, so as to prevent the electrode frompeeling and improve stability of the products. Transparent electrode hashigh light transmittance ratio, thus the light emitting efficiency ofthe micro light emitting diode can be improved. The Micro-LED device mayfurther include an electrode extension part 303 located above thetransparent electrode 301 and electrically connected to the electrode302.

The sidewall current limiting area 201, the second current limiting area202 and the third current limiting area 203 may be formed through ionimplantation technique. Ion implantation technique can increase surfaceflatness and improve stability of the products.

Besides, the sidewall current limiting area 201, the second currentlimiting area 202 and the third current limiting area 203 may be formedthrough diffusion technique or thin film deposition technique.

The upper surface of the sidewall current limiting area has a firstwidth T-up greater than or equal to 1 micrometer.

The light emitting layer includes single-layer quantum well structure ormulti-layer quantum well structure.

Optionally, the light emitting layer includes single-layer quantum wirestructure or multi-layer quantum wire structure.

Optionally, the light emitting layer includes single layer quantum dotstructure or multi-layer quantum dot structure.

The Micro-LED device may further include a back electrode 304 locatedbelow the first type semiconductor layer and electrically connected tothe first type semiconductor layer.

The sidewall current limiting area 201, the second current limiting area202 and/or the third current limiting area 203 may be formed throughmetal organic chemical vapor phase deposition (MOCVD) epitaxy regrowthtechnique.

Optionally, the sidewall current limiting area 201, the second currentlimiting area 202 and/or the third current limiting area 203 may beformed through molecular beam epitaxy (MBE) of epitaxy regrowthtechnique.

Optionally, the sidewall current limiting area 201, the second currentlimiting area 202 and/or the third current limiting area 203 may beformed through atomic layer chemical vapor deposition system (ALD)technique.

Optionally, the sidewall current limiting area 201, the second currentlimiting area 202 and/or the third current limiting area 203 may beformed through laser surface modification technique.

The upper surface 201-up of the sidewall current limiting area 201 andthe outer surface 201-out of the sidewall current limiting area 201 havea first included angle Θ1, the upper surface 201-up of the sidewallcurrent limiting area 201 and the inner surface 201-in of the sidewallcurrent limiting area 201 have a second included angle Θ2, the firstincluded angle Θ1 is an acute angle which is less than 90 degrees, andthe second included angle Θ2 is an obtuse angle which is greater than 90degrees.

Alternatively, the upper surface 201-up of the sidewall current limitingarea 201 and the outer surface 201-out of the sidewall current limitingarea 201 have a first included angle Θ1, the upper surface 201-up of thesidewall current limiting area 201 and the inner surface 201-in of thesidewall current limiting area 201 have a second included angle Θ2, thefirst included angle Θ1 is an obtuse angle which is greater than 90degrees, and the second included angle Θ2 is an acute angle which isless than 90 degrees.

The sidewall current limiting area 201, the second current limiting area202 and/or the third current limiting area 203 may be formed throughselective oxidation technique.

Optionally, the sidewall current limiting area 201, the second currentlimiting area 202 and/or the third current limiting area 203 may beformed through thermal oxidation technique.

Optionally, the sidewall current limiting area 201, the second currentlimiting area 202 and/or the third current limiting area 203 may beformed through wet thermal oxidation technique.

The fabrication method of a Micro-LED device according to an embodimentof the present invention includes forming the above-mentioned microlight emitting diodes on a growth substrate 100, wherein the steps offorming the micro light emitting diodes includes: forming an electrodeelectrically connected to the second type semiconductor layers; bondingthe micro light emitting diodes to a test substrate; removing the growthsubstrate;

forming another electrode electrically connected to the first typesemiconductor layers; providing a voltage source to performelectroluminescence (EL) test to each of the micro light emittingdiodes, and recording the positions of the abnormal micro light emittingdiodes; performing a first selectively removing process to selectivelyremove the abnormal micro light emitting diodes and leaving the microlight emitting diodes passing the test on the test substrate; performinga first transferring process to transfer the micro light emitting diodespassing the test to a permanent substrate and remain the vacancy of theremoved abnormal micro light emitting diodes on the permanent substrate;and performing a second transferring process to transfer micro lightemitting diodes to fill the vacancy on the permanent substrate.

The abnormal micro light emitting diodes can be removed by performing amassive test in advance before massive transfer, thereby improving theyields of massive transfer, such that extra cost of repairing aftermassive transfer can be saved.

A sacrificing layer (700) shown in FIG. 9-6, FIG. 10-6 or FIG. 28-6 maybe further included. The micro light emitting diodes can be bonded tothe test substrate through the sacrificing layer. The first selectivelyremoving process to remove the abnormal micro light emitting diodes canbe carried out by introducing a laser to adjust the adhesiveness of thesacrificing layer, so as to remove the abnormal micro light emittingdiodes from the test substrate. The first transferring process may becarried out by introducing a laser to adjust the adhesiveness of thesacrificing layer, so as to transfer the micro light emitting diodesfrom the test substrate to the permanent substrate. The secondtransferring process can be carried out by introducing a laser to adjustthe adhesiveness of the sacrificing layer, so as to transfer the microlight emitting diodes from the test substrate to the permanentsubstrate. By adopting the laser to adjust the adhesiveness of thesacrificing layer, the rate of massive transfer can be improved,production cost can be reduced, and the yields can be improved.

The micro light emitting diodes transferred in the first transferringprocess and the micro light emitting diodes transferred in the secondtransferring process may come from the same growth substrate or fromdifferent growth substrates.

The advantages of the above-mentioned fabrication method include:

(1) The chips from the same epitaxial wafer has similar wavelengths,which can increase the rate of massive transfer.

(2) Waste of the chip materials can be reduced, utility rate of thesource chips can be increased, and production cost can be reduced.

The fabrication method of the above-mentioned Micro-LED device mayinclude adopting a magnetic bonding layer to temporarily bond the microlight emitting diodes to the test substrate. In such condition, thefirst selectively removing process to the abnormal micro light emittingdiodes may be carried out by adjusting the magnetic force of themagnetic bonding layer, so as to remove the abnormal micro lightemitting diodes from the test substrate. The first transferring processmay be carried out by adjusting the magnetic force of the magneticbonding layer, so as to transfer the micro light emitting diodes fromthe test substrate to the permanent substrate. The second transferringprocess may be carried out by adjusting the magnetic force of themagnetic bonding layer, so as to transfer the micro light emittingdiodes from the test substrate to the permanent substrate. By adoptingthe magnetic bonding layer, the rate and yields of testing andtransferring can be improved, and production cost can be reduced.

Optionally, the fabrication method of the Micro-LED device may includeadopting a vacuum adsorption layer to bond the micro light emittingdiodes to the test substrate. In such case, the first selectivelyremoving process for selectively removing the abnormal micro lightemitting diodes can be carried out by adjusting the suction of thevacuum adsorption layer, such that the abnormal micro light emittingdiodes can be removed from the test substrate. The first transferringprocess can be carried out by adjusting the suction of the vacuumadsorption layer, such that the micro light emitting diodes can betransferred from the test substrate to the permanent substrate. Thesecond transferring process can be carried out by adjusting the suctionof the vacuum adsorption layer, such that the micro light emittingdiodes can be transferred from the test substrate to the permanentsubstrate. By adopting the vacuum adsorption layer, the rate and yieldsof testing and transferring can be improved, and production cost can bereduced.

Optionally, the fabrication method of the Micro-LED device may includeadopting an electrostatic adsorption layer to bond the micro lightemitting diodes to the test substrate. In such case, the firstselectively removing process for selectively removing the abnormal microlight emitting diodes can be carried out by adjusting the electrostaticforce of the electrostatic adsorption layer, such that the abnormalmicro light emitting diodes can be removed from the test substrate. Thefirst transferring process can be carried out by adjusting theelectrostatic force of the electrostatic adsorption layer, such that themicro light emitting diodes can be transferred from the test substrateto the permanent substrate. The second transferring process can becarried out by adjusting the electrostatic force of the electrostaticadsorption layer, such that the micro light emitting diodes can betransferred from the test substrate to the permanent substrate. Byadopting the electrostatic adsorption layer, the rate and yields oftesting and transferring can be improved, and production cost can bereduced.

Optionally, the fabrication method of the Micro-LED device may includeadopting an adhesion layer to bond the micro light emitting diodes tothe test substrate. In such case, the first selectively removing processfor removing the abnormal micro light emitting diodes can be carried outby adjusting the adhesion of the adhesion layer, such that the abnormalmicro light emitting diodes can be removed from the test substrate. Thefirst transferring process can be achieved by adjusting the adhesion ofthe adhesion layer, such that the micro light emitting diodes can betransferred from the test substrate to the permanent substrate. Thesecond transferring process of can be carried out by adjusting theadhesion of the adhesion layer, such that the micro light emittingdiodes can be transferred from the test substrate to the permanentsubstrate. By adopting the adhesion layer, the rate and yields oftesting and transferring can be improved, and production cost can bereduced.

The above-mentioned fabrication method of the Micro-LED device includesthe following features: the first selectively removing process to theabnormal micro light emitting diodes has a first removal rate; the firsttransferring process for transferring the micro light emitting diodespassing the test to the permanent substrate has a first transfer rate;and the second transferring process for filling the vacancy on thepermanent substrate has a second transfer rate; wherein the firsttransfer rate is greater than the second transfer rate, and the firstremoval rate is greater than or equal to the second transfer rate.

The above-mentioned fabrication method of the Micro-LED device mayfurther adopt the following methods: the first transferring process fortransferring the micro light emitting diodes passing the test to thepermanent substrate has a first transfer rate; and the secondtransferring process for filling the vacancy on the permanent substratehas a second transfer rate; wherein the first transfer rate is greaterthan the second transfer rate. By controlling the transfer rate and theremoval rate, the yields of massive transfer can be improved, andproduction cost can be reduced.

According to the fabrication method of Micro-LED device, the micro lightemitting diodes on the growth substrate 100 have a first pitch P1; themicro light emitting diodes on the permanent substrate 820 have a secondpitch P2; and the second pitch P2 is greater than or equal to the firstpitch P1.

Subsequent production cost can be reduced by controlling the transferpitch.

In the above-mentioned fabrication method of Micro-LED device, the microlight emitting diodes at least include an array structure composed ofred LEDs, green LEDs and blue LEDs. In such case, the fabrication methodfurther includes: forming a wall structure 850 located between adjacentmicro light emitting diodes; and forming a light-transmissive adhesive Fcovering the micro light emitting diodes. The wall structure 850 canimprove the display contrast of the micro-LED display.

The micro light emitting diodes at least include an array structurecomposed of ultraviolet LEDs.

The above-mentioned fabrication method of the Micro-LED device furtherincludes:

forming a wall structure 850 located between the adjacent micro lightemitting diodes; forming a first phosphor with adhesive F1 covering oneor more of the micro light emitting diodes, wherein the first phosphorwith adhesive F1 is excited by the micro light emitting diodes to emitred light; forming a second phosphor with adhesive F2 covering one ormore of the micro light emitting diodes, wherein the second phosphorwith adhesive F2 is excited by the micro light emitting diodes to emitblue light; and forming a third phosphor with adhesive F3 covering oneor more of the micro light emitting diodes, wherein the third phosphorwith adhesive F3 is excited by the micro light emitting diodes to emitgreen light.

The micro light emitting diodes at least include an array structurecomposed of blue LEDs.

Optionally, the above-mentioned fabrication method of the Micro-LEDdevice further includes: forming a wall structure 850 located betweenthe adjacent micro light emitting diodes; forming a firstlight-transmissive adhesive F covering one or more of the micro lightemitting diodes, wherein blue light is emitted from the micro lightemitting diodes which penetrates the first light-transmissive adhesiveF; forming a first phosphor with adhesive F1 covering one or more of themicro light emitting diodes, wherein the first phosphor with adhesive F1is excited by the micro light emitting diodes to emit red light; andforming a third phosphor with adhesive F3 covering one or more of themicro light emitting diodes, wherein the third phosphor with adhesive F3is excited by the micro light emitting diodes to emit green light.

The light emitting efficiency of the micro light emitting diodes isgreater than 250 lm/W.

The reveal ability to red, R9, of the color rendering index (CRI) of themicro light emitting diode is greater than 90.

The CRI of the micro light emitting diodes is greater than 90.

The general CRI Ra of the micro light emitting diodes is greater than90.

The permanent substrate 820 is a flexible substrate, wherein thematerial of the flexible substrate may include ultra-thin glass, metalfoil, fiber-reinforced composite material, plastic film, ceramicsubstrate or a combination of any two or more of the above-mentionedmaterials. The flexible substrate can be applied in flexible display.Preferably, the coefficient of thermal expansion (CTE) of the metal foilis similar to CTE of the thin glass. The light transmittance of theplastic film is greater than 90% under a wavelength of 550 nanometers.The material of the plastic film may for example include polyethyleneterephthalate (PET), polyethylene naphthalate (PEN) or polyethersulfone(PES). The fiber-reinforced composite material may for example includecarbon fibers, silicon carbide fibers or boron filament.

The preferred thickness of the flexible substrate is less than 200micrometers, the more preferred thickness of the flexible substrate isless than 50 micrometers, and the best thickness of the flexiblesubstrate is in a range from 25 micrometers to 50 micrometers.

The metal foil may for example include stainless steel, aluminum,nickel, titanium, zirconium, copper, iron, cobalt, palladium or acombination of any two or more of the above-mentioned materials.

The surface roughness Ra of the metal foil is less than 10 nanometers.

The permanent substrate 820 may be a transparent substrate, and thetransparent substrate may for example be formed of normal glass, hardglass, quartz, ceramic or plastic.

The fabrication method of another Micro-LED device according to anembodiment of the present invention includes forming the above-mentionedmicro light emitting diodes on a growth substrate, wherein the steps offorming the micro light emitting diodes includes: forming an electrodeelectrically connected to the second type semiconductor layer; bondingthe micro light emitting diodes to a test substrate; removing the growthsubstrate; forming another electrode electrically connected to the firsttype semiconductor layer; providing a voltage source to performelectroluminescence (EL) test to each of the micro light emittingdiodes, and recording the positions of the abnormal micro light emittingdiodes; performing a first selectively removing process to remove theabnormal micro light emitting diodes and leave the micro light emittingdiodes passing the test on the test substrate; performing a firsttransferring process to transfer the micro light emitting diodes passingthe test to a first container; the first container includes a firstliquid covering the micro light emitting diodes; and performing a secondtransferring process to transfer the micro light emitting diodes to areceiving substrate.

The beneficial effects of the fabrication method are as following:

(1) Repairing cost after transferring process can be saved by performingelectroluminescence test to each of the micro light emitting diodesbefore transferring.

(2) Fluid transfer has advantages such as low cost and high transferrate.

The second transferring process can be carried out by adjusting the flowrate of the first liquid so as to transfer the micro light emittingdiodes to the receiving substrate.

The second transferring process can also be carried out by adjusting theviscosity of the first liquid so as to transfer the micro light emittingdiodes to the receiving substrate.

The second transferring process can also be carried out by adjustingsubstrate capturing rate so as to transfer the micro light emittingdiodes to the receiving substrate. Massive transfer can be achieved bycontrolling the flow rate and viscosity of the liquid and adjusting thesubstrate capturing rate.

The fabrication method of the Micro-LED device further includesproviding a sacrificing layer 700 as shown in FIG. 9-6, FIG. 10-6 orFIG. 28-6 for bonding the micro light emitting diodes to the testsubstrate through the sacrificing layer. In such case, the firstselectively removing process to remove the abnormal micro light emittingdiodes can be carried out by introducing a laser to adjust theadhesiveness of the sacrificing layer, so as to remove the abnormalmicro light emitting diodes from the test substrate. The firsttransferring process can be carried out by introducing a laser to adjustthe adhesiveness of the sacrificing layer, so as to transfer the microlight emitting diodes from the test substrate to the first container. Byadopting the sacrificing layer and laser, the rate and yields of testingand transferring can be improved, and production cost can be reduced.

The micro light emitting diodes transferred in the first transferringprocess and the micro light emitting diodes transferred in the secondtransferring process come from the same growth substrate. Alternatively,the micro light emitting diodes transferred in the first transferringprocess and the micro light emitting diodes transferred in the secondtransferring process come from different growth substrates.

The advantages of the above-mentioned method are as following:

(1) The chips from the same epitaxial wafer has a similar wavelength,which can increase the rate of massive transfer.

(2) Waste of the chip materials can be reduced, utility rate of thesource chip can be increased, and production cost can be reduced.

The fabrication method of the Micro-LED device may further includeadopting a magnetic bonding layer to bond the micro light emittingdiodes to a test substrate. In such case, the first selectively removingprocess for removing the abnormal micro light emitting diodes can becarried out by adjusting the magnetic force of the magnetic bondinglayer, so as to remove the abnormal micro light emitting diodes from thetest substrate. The first transferring process can be carried out byadjusting the magnetic force of the magnetic bonding layer, so as totransfer the micro light emitting diodes from the test substrate to thefirst container. By adopting the magnetic bonding layer, the rate andyields of testing and transferring can be improved, and production costcan be reduced.

Optionally, the fabrication method of the Micro-LED device may includeadopting a vacuum adsorption layer to bond the micro light emittingdiodes to the test substrate. In such case, the first selectivelyremoving process for removing the abnormal micro light emitting diodescan be carried out by adjusting the suction of the vacuum adsorptionlayer, so as to remove the abnormal micro light emitting diodes from thetest substrate. The first transferring process can be carried out byadjusting the suction of the vacuum adsorption layer, so as to transferthe micro light emitting diodes from the test substrate to the firstcontainer. By adopting the vacuum adsorption layer, the rate and yieldsof testing and transferring can be improved, and production cost can bereduced.

Optionally, the fabrication method of the Micro-LED device may includeadopting an electrostatic adsorption layer to bond the micro lightemitting diodes to the test substrate. In such case, the firstselectively removing process for removing the abnormal micro lightemitting diodes can be carried out by adjusting the electrostatic forceof the electrostatic adsorption layer, so as to remove the abnormalmicro light emitting diodes from the test substrate. The firsttransferring process can be carried out by adjusting the electrostaticforce of the electrostatic adsorption layer, so as to transfer the microlight emitting diodes from the test substrate to the first container. Byadopting the electrostatic adsorption layer, the rate and yields oftesting and transferring can be improved, and production cost can bereduced.

Optionally, the fabrication method of the Micro-LED device may includeadopting an adhesion layer to bond the micro light emitting diodes tothe test substrate. In such case, the first selectively removing processfor removing the abnormal micro light emitting diodes can be carried outby adjusting the adhesion of the adhesion layer, so as to remove theabnormal micro light emitting diodes from the test substrate. The firsttransferring process can be carried out by adjusting the adhesion of theadhesion layer, so as to transfer the micro light emitting diodes fromthe test substrate to the first container. By adopting the adhesionlayer, the rate and yields of testing and transferring can be improved,and production cost can be reduced.

According to the fabrication method of the Micro-LED device, the firstselectively removing process for the abnormal micro light emittingdiodes has a first removal rate;

the first transferring process for transferring the micro light emittingdiodes passing the test to the first container has a first transferrate; and

the second transferring process for transferring the micro lightemitting diodes to a receiving substrate has a second transfer rate;wherein the first transfer rate is greater than the second transferrate, and the first removal rate is greater than or equal to the secondtransfer rate.

By controlling the transfer rate and removal rate, the yields of massivetransfer can be improved, and production cost can be reduced.

Optionally, according to the fabrication method of the Micro-LED device,the first transferring process for transferring the micro light emittingdiodes passing the test to the first container has a first transferrate; and

the second transferring process for transferring the micro lightemitting diodes to a receiving substrate has a second transfer rate;wherein the first transfer rate is greater than the second transferrate.

According to the fabrication method of the Micro-LED device, the microlight emitting diodes on the growth substrate 100 have a first pitch P1;and the micro light emitting diodes on the receiving substrate 830 havea second pitch P2; wherein the second pitch P2 is greater than or equalto the first pitch P1.

Optionally, in the fabrication method of the Micro-LED device, the microlight emitting diodes on the growth substrate 100 have a first pitch P1;and the micro light emitting diodes on the receiving substrate 830 havea second pitch P2; wherein the second pitch P2 is greater than the firstpitch P1. Subsequent production cost can be reduced by controlling thetransfer pitch.

In the fabrication method of the Micro-LED device, the micro lightemitting diodes at least include an array structure composed of redLEDs, green LEDs and blue LEDs. In such case, the fabrication methodfurther includes: forming a wall structure 850 located between adjacentmicro light emitting diodes; and forming a light-transmissive adhesive Fcovering the micro light emitting diodes. The wall structure 850 canimprove display contrast of the micro-LED display.

The micro light emitting diodes at least include an array structurecomposed of ultraviolet LEDs. In such case, the fabrication methodfurther includes: forming a wall structure 850 located between adjacentmicro light emitting diodes; forming a first phosphor with adhesive F1covering one or more of the micro light emitting diodes, wherein thefirst phosphor with adhesive F1 emits red light when it is excited bythe micro light emitting diodes; forming a second phosphor with adhesiveF2 covering one or more of the micro light emitting diodes, wherein thesecond phosphor with adhesive F2 emits blue light when it is excited bythe micro light emitting diodes; and forming a third phosphor withadhesive F3 covering one or more of the micro light emitting diodes,wherein the third phosphor with adhesive F3 emits green light when it isexcited by the micro light emitting diodes.

The micro light emitting diodes at least includes an array structurecomposed of blue LEDs. In such case, the fabrication method furtherincludes: forming a wall structure 850 located between adjacent microlight emitting diodes; forming a first light-transmissive adhesive Fcovering one or more of the micro light emitting diodes, wherein bluelight is emitted from the micro light emitting diodes which penetratesthe first light-transmissive adhesive F; forming a first phosphor withadhesive F1 covering one or more of the micro light emitting diodes,wherein the first phosphor with adhesive F1 emits red light when it isexcited by the micro light emitting diodes; and forming a third phosphorwith adhesive F3 covering one or more of the micro light emittingdiodes, wherein the third phosphor with adhesive F3 emits green lightwhen it is excited by the micro light emitting diodes.

Light emitting efficiency of the micro light emitting diodes is greaterthan 250 lm/W.

The reveal ability to red, R9, of the color rendering index (CRI) of themicro light emitting diodes is greater than 90.

The CRI of the micro light emitting diodes is greater than 90.

The general CRI Ra of the micro light emitting diodes is greater than90.

The fabrication method of another Micro-LED device includes forming theabove-mentioned micro light emitting diodes on a growth substrate,wherein the steps of forming the micro light emitting diodes includes:forming an electrode electrically connected to the second typesemiconductor layer; bonding the micro light emitting diodes to a testsubstrate; removing the growth substrate;

forming another electrode electrically connected to the first typesemiconductor layer; providing a voltage source to performelectroluminescence (EL) test to each of the micro light emittingdiodes, and record the positions of the abnormal micro light emittingdiodes; selectively removing the abnormal micro light emitting diodes,and leaving the micro light emitting diodes passing the test; the microlight emitting diodes include the micro light emitting diodes with afirst color, the micro light emitting diodes with a second color, andthe micro light emitting diodes with a third color; transferring themicro light emitting diodes with the first color passing the test to afirst container, and putting the first container in a first sub-chamber,wherein the first sub-chamber includes a liquid covering the micro lightemitting diodes with the first color; transferring the micro lightemitting diodes with the second color passing the test to a secondcontainer, and putting the second container in a second sub-chamber,wherein the second sub-chamber includes a liquid covering the microlight emitting diodes with the second color; transferring the microlight emitting diodes with the third color passing the test to a thirdcontainer, and putting the third container in a third sub-chamber,wherein the third sub-chamber includes a liquid covering the micro lightemitting diodes with the third color; and transferring the micro lightemitting diodes with the first color, the micro light emitting diodeswith the second color and the micro light emitting diodes with the thirdcolor to a receiving substrate through a fluid transfer systemrespectively.

The beneficial effects of the method are as following:

(1) Repairing cost after the transferring process can be saved byperforming electroluminescence test to each of the micro light emittingdiodes before the transferring process.

(2) Fluid transfer has advantages such as low cost and high transferrate.

(3) By the design of the first sub-chamber, the second sub-chamber andthe third sub-chamber, the micro light emitting diodes with differentcolors can be respectively transferred in batches, and production ratecan be improved.

The receiving substrate has a plurality of recesses thereon, and aplurality of controllable attraction layers are disposed in thereceiving substrate. The attraction layer may provide an electricalattraction force, a magnetic attraction force, an electrostaticattraction force, a fluid attraction force, an air attraction force, avan der waals attraction force, a thermal attraction force and anattachment attraction force. The attraction force produced by theattraction layer can capture the micro light emitting diodes in thefluid. In such case, the fluid transfer system includes a firstsub-chamber, a second sub-chamber and a third sub-chamber. The firstsub-chamber includes a plurality of micro light emitting diodes with thefirst color, a solution, a first valve and a first input port. When thefirst valve is opened, the plurality of micro light emitting diodes withthe first color are moved downward through the first valve to a mainchamber by the solution injected from the first input port, andrespectively moved to the corresponding recess above the substrate bythe fluid. The micro light emitting diodes with the first color may beattracted by the suction of the attraction layer on the substrate tomove to the recesses in a self-alignment way, wherein the shape of therecesses and the shape of the micro light emitting diodes with the firstcolor are the same. Accordingly, transfer of the micro light emittingdiodes with the first color to the top of the substrate can beaccomplished.

The second sub-chamber includes a plurality of micro light emittingdiodes with the second color, a solution, a second valve and a secondinput port. When the second valve is opened, the plurality of microlight emitting diodes with the second color are moved downward throughthe second valve to a main chamber by the solution injected from thesecond input port, and respectively moved to the corresponding recessabove the substrate by the fluid. The micro light emitting diodes withthe second color may be attracted by the suction of the attraction layeron the substrate to move to the recesses in a self-alignment way,wherein the shape of the recesses and the shape of the micro lightemitting diodes with the second color are the same. Accordingly,transfer of the micro light emitting diodes with the second color to thetop of the substrate can be accomplished.

The beneficial effects of the above-mentioned method are as following:

(1) Repairing cost after the transferring process can be saved byperforming electroluminescence test to each of the micro light emittingdiodes before the transferring process.

(2) Fluid transfer has advantages such as low cost and high transferrate.

(3) By the design of the first sub-chamber, the second sub-chamber andthe third sub-chamber, the micro light emitting diodes with differentcolors can be respectively transferred in batches, and production ratecan be improved.

(4) The design of self-alignment to the recesses can reduce productioncost.

The third sub-chamber includes a plurality of micro light emittingdiodes with the third color, a solution, a third valve and a third inputport. When the third valve is opened, the plurality of micro lightemitting diodes with the third color are moved downward through thethird valve to a main chamber by the solution injected from the thirdinput port, and respectively moved to the corresponding recess above thesubstrate by the fluid. The micro light emitting diodes with the thirdcolor may be attracted by the suction of the attraction layer on thesubstrate to move to the recess in a self-alignment way, wherein theshape of the recess and the shape of the micro light emitting diodeswith the third color are the same. Accordingly, transfer of the microlight emitting diodes with the third color to the top of the substratecan be accomplished.

A further Micro-LED device according to an embodiment of the presentinvention includes a first type semiconductor layer 101, a second typesemiconductor layer 102, a light emitting layer 103 located between thefirst type semiconductor layer 101 and the second type semiconductorlayer 102 and a first current limiting area 201 located at a peripheryof the second type semiconductor layer 102 and the sidewall region ofthe second type semiconductor layer 102. The first current limiting area201 can reduce sidewall leakage current, and the light emittingefficiency of the micro light emitting diode can be improved.

The upper surface U6 of the second type semiconductor layer 102 and theupper surface U1 of the first current limiting area 201 are coplanar.

The above-mentioned Micro-LED device may further include a transparentelectrode 301 located above the second type semiconductor layer 102 andelectrically connected to the second type semiconductor layer 102, andthe transparent electrode 301 covers the first current limiting area201. In such case, the Micro-LED device may further include an electrode302 located above the second type semiconductor layer 102 andelectrically connected to the transparent electrode 301, and theelectrode 302 is directly in contact with the second type semiconductorlayer 102, thereby preventing the electrode from peeling, and stabilityof the products can be improved. The Micro-LED device may furtherinclude another electrode 304 located above the first type semiconductorlayer 101 and the second type semiconductor layer 102 and electricallyconnected to the first type semiconductor layer 101, and the anotherelectrode 304 is directly in contact with the first type semiconductorlayer 102. The transparent electrode 301 has high light transmittanceratio, thereby improving the light emitting efficiency of the microlight emitting diode. The Micro-LED device may further include a fifthcurrent blocking area 505 covering the transparent electrode 301 andisolating the electrode 302 and the another electrode 304. The anotherelectrode 304 has a fourth width T4, the electrode has a fifth width T5,and the fourth width T4 is greater than or equal to the fifth width T5.The contact surface between the another electrode 304 and the first typesemiconductor layer 101 has a third width T3, and the third width T3 isless than the fourth width T4.

The first current limiting area 201 can be formed through ionimplantation technique. Ion implantation technique can increase sidewallflatness and improve stability of the products.

The first current limiting area 201 has a first width T1 greater than orequal to 1 micrometer.

The Micro-LED device may include an etching groove 105 formed byremoving a portion of the second type semiconductor layer 102 and thelight emitting layer 103, and the groove 105 exposes the first typesemiconductor layer 101. The groove 105 has a seventh depth D7, thefirst current limiting area has a first depth D1, and the first depth D1is less than or equal to the seventh depth D7. The Micro-LED device hasa feature of flip chip structure. In such case, the Micro-LED devicefurther includes a fifth current blocking area 505 located at thesidewall of the etching groove 105.

The first type semiconductor layer 101, the second type semiconductorlayer 102 and the light emitting layer 103 have an epitaxial thicknessE1 less than 10 micrometers.

The Micro-LED device may include a sixth current blocking area 506covering the sidewall of the second type semiconductor layer 102, thesidewall of the light emitting layer 103 and the sidewall of the firsttype semiconductor layer 101, and the sixth current blocking area 506surrounds the first current limiting area 201.

The Micro-LED device may include a fourth current limiting area 204surrounded by the first current limiting area 201, wherein the firstcurrent limiting area 201 has a first depth D1, the fourth currentlimiting area 204 has a fourth depth D4, and the first depth D1 is equalto the fourth depth D4. In such case, the fourth current limiting area204 can be formed through ion implantation technique. The upper surfaceU4 of the fourth current limiting area 204 and the upper surface U6 ofthe second type semiconductor layer 102 are coplanar. The fifth currentlimiting area 205 can be formed through ion implantation technique. Theupper surface U5 of the fifth current limiting area 205 and the uppersurface U6 of the second type semiconductor layer 102 are coplanar.

The Micro-LED device may include a fifth current limiting area 205surrounded by the first current limiting area 201, wherein the firstcurrent limiting area 201 has a first depth D1, the fifth currentlimiting area 205 has a fifth depth D5, the first depth D1 is equal tothe fifth depth D5, and the fifth current limiting area 205 surroundsthe etching groove 105.

The Micro-LED device may include a fourth current blocking area 504surrounded by the first current limiting area 201 and directly incontact with the second type semiconductor layer 102.

The periphery of the first current limiting area 201 has a first lengthS1, a second length S2, a third length S3 and a fourth length S4,wherein the first length S1, the second length S2, the third length S3and the fourth length S4 are less than or equal to 100 micrometersrespectively.

The periphery of the first current limiting area 201 has a first lengthS1, a second length S2, a third length S3 and a fourth length S4,wherein the summation of the first length S1, the second length S2, thethird length S3 and the fourth length S4 is less than or equal to 400micrometers.

The light emitting efficiency of the micro light emitting diodes isgreater than 250 lm/W.

The reveal ability to red, R9, of the color rendering index (CRI) of themicro light emitting diodes is greater than 90.

The CRI of the micro light emitting diodes is greater than 90.

The general CRI Ra of the micro light emitting diodes is greater than90.

The periphery perimeter of the first current limiting area 201 is lessthan or equal to 400 micrometers. Optionally, the periphery perimeter ofthe first current limiting area 201 is less than or equal to 200micrometers. Optionally, the periphery perimeter of the first currentlimiting area 201 is less than or equal to 100 micrometers. Optionally,the periphery perimeter of the first current limiting area 201 is lessthan or equal to 50 micrometers. Optionally, the periphery perimeter ofthe first current limiting area 201 is less than or equal to 20micrometers.

For example, the materials used in the above-mentioned ion implantationtechnique may include ions H⁺, He⁺, N⁺, F⁺, Mg⁺, Ar⁺, Zn⁺, O⁺, Si⁺, P⁺,Be⁺, C⁺, B⁺, P⁺, As⁺, Sb⁺, Te⁺, Fe⁺, Co⁺, Sn⁺, Zr⁺, Ag⁺, Au⁺, Ti⁺, Al⁺or the combination thereof, but not limited thereto. In the ionimplantation technique, the ions are passed through the mass analyzer toremove unwanted ions by using a magnetic field at first, and then, afterthe selected doping ions enter the accelerator, the ions are acceleratedto have high energy by the electric field. Sequentially, after thehigh-energy ion-beam passes through the longitudinal and lateralscanners, the ion-beam is driven into the semiconductor to perform thepre-set of the doping ions. When performing the pre-set of the dopingions, the doping concentration of the pre-set can be controlled by thecurrent intensity of the ion beam and implantation time. Thedistribution of the dopants in the semiconductor can be adjusted by theenergy obtained by the ions through acceleration. Accordingly, theconcentration and distribution of the doping ions in the semiconductorcan be precisely controlled. After the ion implantation process,annealing activation may be performed by adopting rapid thermalannealing (RTA) or high-temperature furnace to repair the destructionand disorder of the lattice caused by collision, and the implanted ionsand the atoms of the semiconductor can be recrystallized, such that theimplanted ions can be located at the positions of the main atoms in newlattice.

The first type semiconductor layer 101, the second type semiconductorlayer 102 and the light emitting layer 103 of the above-mentioned microlight emitting diodes may include any materials, for example includinggallium nitride (GaN), aluminum nitride (AlN), indium nitride (InN),indium gallium nitride (InGaN), aluminum gallium nitride (AlGaN),aluminumgallium indium nitride (AlGaInN), gallium phosphide (GaP),aluminum phosphide (AlP), aluminum gallium phosphide (AlGaP), aluminumarsenide (AlAs), aluminum gallium arsenide (AlGaAs), aluminumindiumgallium phosphide (AlInGaP), aluminumindium gallium arsenide (AlInGaAs),zinc selenide (ZnSe), zinc oxide (ZnO) or the alloy thereof, but notlimit thereto.

Each of the micro light emitting diodes in the above-mentioned microlight emitting diodes can be controlled independently.

The fabrication method of a Micro-LED device includes forming theabove-mentioned micro light emitting diodes on a growth substrate,wherein the steps of forming the micro light emitting diodes includes:forming an electrode electrically connected to the second typesemiconductor layer; forming another electrode electrically connected tothe first type semiconductor layer; bonding the micro light emittingdiodes to a test substrate; removing the growth substrate; providing avoltage source to perform electroluminescence (EL) test to each of themicro light emitting diodes, and record the positions of the abnormalmicro light emitting diodes;

transferring the micro light emitting diodes to a transfer substrate;performing a first selectively removing process to selectively removethe abnormal micro light emitting diodes, and remain the micro lightemitting diodes passing the test; performing a first transferringprocess to transfer the micro light emitting diodes passing the test toa permanent substrate, and remain the vacancy of the removed abnormalmicro light emitting diodes on the permanent substrate; and performing asecond transferring process to fill the vacancy on the permanentsubstrate.

The fabrication method of the Micro-LED device further includes adoptinga sacrificing layer 700 as shown in FIG. 9-6, FIG. 10-6 or FIG. 28-6.The micro light emitting diodes can be bonded to the test substratethrough the sacrificing layer. The first selectively removing processfor removing the abnormal micro light emitting diodes can be carried outby introducing a laser to adjust the adhesiveness of the sacrificinglayer, so as to remove the abnormal micro light emitting diodes from thetest substrate. The first transferring process can be carried out byintroducing a laser to adjust the adhesiveness of the sacrificing layer,so as to transfer the micro light emitting diodes from the testsubstrate to the permanent substrate. The second transferring processcan be carried out by introducing a laser to adjust the adhesiveness ofthe sacrificing layer, so as to transfer the micro light emitting diodesfrom the test substrate to the permanent substrate. The micro lightemitting diodes transferred in the first transferring process and themicro light emitting diodes transferred in the second transferringprocess come from different growth substrate. The fabrication method ofthe Micro-LED device further includes adopting a magnetic bonding layerto temporarily bond the micro light emitting diodes to the testsubstrate. In such case, the first selectively removing process forremoving the abnormal micro light emitting diodes can be carried out byadjusting the magnetic force of the magnetic bonding layer, so as toremove the abnormal micro light emitting diodes from the test substrate.The first transferring process can be carried out by adjusting themagnetic force of the magnetic bonding layer, so as to transfer themicro light emitting diodes from the test substrate to the permanentsubstrate. The second transferring process can be carried out byadjusting the magnetic force of the magnetic bonding layer, so as totransfer the micro light emitting diodes from the test substrate to thepermanent substrate.

The fabrication method of the Micro-LED device may further includeadopting a vacuum adsorption layer to bond the micro light emittingdiodes to the substrate.

The first selectively removing process for removing the abnormal microlight emitting diodes can be carried out by adjusting the suction of thevacuum adsorption layer, so as to remove the abnormal micro lightemitting diodes from the test substrate. The first transferring processcan be carried out by adjusting the suction of the vacuum adsorptionlayer, so as to transfer the micro light emitting diodes from the testsubstrate to the permanent substrate. The second transferring processcan be carried out by adjusting the suction of the vacuum adsorptionlayer, so as to transfer the micro light emitting diodes from the testsubstrate to the permanent substrate.

The micro light emitting diodes transferred in the first transferringprocess and the micro light emitting diodes transferred in the secondtransferring process come from the same growth substrate.

Optionally, the fabrication method of the Micro-LED device may includeadopting an electrostatic adsorption layer to bond the micro lightemitting diodes to a test substrate. In such case, the first selectivelyremoving process for removing the abnormal micro light emitting diodescan be carried out by adjusting the electrostatic force of theelectrostatic adsorption layer, so as to remove the abnormal micro lightemitting diodes from the test substrate. The first transferring processcan be carried out by adjusting the electrostatic force of theelectrostatic adsorption layer, so as to transfer the micro lightemitting diodes from the test substrate to the permanent substrate. Thesecond transferring process can be carried out by adjusting theelectrostatic force of the electrostatic adsorption layer, so as totransfer the micro light emitting diodes from the test substrate to thepermanent substrate.

Optionally, the fabrication method of the Micro-LED device may includeadopting an adhesion layer to bond the micro light emitting diodes to atest substrate. In such case, the first selectively removing process forremoving the abnormal micro light emitting diodes can be carried out byadjusting the adhesion of the adhesion layer, so as to remove theabnormal micro light emitting diodes from the test substrate. The firsttransferring process can be carried out by adjusting the adhesion of theadhesion layer, so as to transfer the micro light emitting diodes fromthe test substrate to the permanent substrate. The second transferringprocess can be carried out by adjusting the adhesion of the adhesionlayer, so as to transfer the micro light emitting diodes from the testsubstrate to the permanent substrate.

In the fabrication method of the Micro-LED device, the first selectivelyremoving process for removing the abnormal micro light emitting diodeshas a first removal rate; the first transferring process fortransferring the micro light emitting diodes passing the test to thepermanent substrate has a first transfer rate; and the secondtransferring process for filling the vacancy on the permanent substratehas a second transfer rate; wherein the first transfer rate is greaterthan the second transfer rate, and the first removal rate is greaterthan or equal to the second transfer rate.

In the fabrication method of the Micro-LED device, the firsttransferring process for transferring the micro light emitting diodespassing the test to the permanent substrate has a first transfer rate;and the second transferring process for filling the vacancy on thepermanent substrate has a second transfer rate; wherein the firsttransfer rate is greater than the second transfer rate.

In the fabrication method of the Micro-LED device, the micro lightemitting diodes on the growth substrate 100 have a first pitch P1; themicro light emitting diodes on the transfer substrate 801 have a secondpitch P2; and the micro light emitting diodes on the permanent substrate820 have a third pitch P3; wherein the second pitch P2 is greater thanor equal to the first pitch P1, and the third pitch P3 is greater thanor equal to the second pitch P2.

Optionally, in the fabrication method of the Micro-LED device, the microlight emitting diodes on the growth substrate 100 have a first pitch P1;the micro light emitting diodes on the transfer substrate 801 have asecond pitch P2; and the micro light emitting diodes on the permanentsubstrate 820 have a third pitch P3; wherein the second pitch P2 isgreater than the first pitch P1, and the third pitch P3 is greater thanthe second pitch P2.

The micro light emitting diodes at least include an array composed ofred LEDs, green LEDs and blue LEDs. The fabrication method of theMicro-LED device further includes: forming a wall structure 850 locatedbetween adjacent micro light emitting diodes; and forming alight-transmissive adhesive F covering the micro light emitting diodes.

Selectively, the micro light emitting diodes at least include an arraystructure composed of ultraviolet LEDs.

The above-mentioned fabrication method further includes: forming a wallstructure 850 located between adjacent micro light emitting diodes;forming a first phosphor with adhesive F1 covering one or more of themicro light emitting diodes, wherein the first phosphor with adhesive F1emits red light when it is excited by the micro light emitting diodes;forming a second phosphor with adhesive F2 covering one or more of themicro light emitting diodes, wherein the second phosphor with adhesiveF2 emits blue light when it is excited by the micro light emittingdiodes; and forming a third phosphor with adhesive F3 covering one ormore of the micro light emitting diodes, wherein the third phosphor withadhesive F3 emits green light when it is excited by the micro lightemitting diodes.

Selectively, the micro light emitting diodes at least include an arraycomposed of blue LEDs. The above-mentioned fabrication method furtherincludes: forming a wall structure 850 located between adjacent microlight emitting diodes; forming a first light-transmissive adhesive Fcovering one or more of the micro light emitting diodes, wherein bluelight emitted by the micro light emitting diodes penetrates the firstlight-transmissive adhesive; forming a first phosphor with adhesive F1covering one or more of the micro light emitting diodes, wherein thefirst phosphor with adhesive F1 emits red light when it is excited bythe micro light emitting diodes; and forming a third phosphor withadhesive F3 covering one or more of the micro light emitting diodes,wherein the third phosphor with adhesive F3 emits green light when it isexcited by the micro light emitting diodes.

The light emitting efficiency of the micro light emitting diodes isgreater than 250 lm/W.

The reveal ability to red, R9, of the color rendering index (CRI) of themicro light emitting diodes is greater than 90.

The CRI of the micro light emitting diode is greater than 90.

The general CRI Ra of the micro light emitting diodes is greater than90.

The first transferring process for transferring the micro light emittingdiodes passing the test to the permanent substrate has a first transferrate, and the first transfer rate is greater than 1 million micro lightemitting diodes per hour (million micro-LEDs/hour).

Optionally, the first transferring process for transferring the microlight emitting diodes passing the test to the permanent substrate has afirst transfer rate, and the first transfer rate is greater than 10million micro-LEDs/hour.

Optionally, the first transferring process for transferring the microlight emitting diodes passing the test to the permanent substrate has afirst transfer rate, and the first transfer rate is greater than 20million micro-LEDs/hour.

Optionally, the first transferring process for transferring the microlight emitting diodes passing the test to the permanent substrate has afirst transfer rate, and the first transfer rate is greater than 100million micro-LEDs/hour.

Optionally, the first transferring process for transferring the microlight emitting diodes passing the test to the permanent substrate has afirst transfer rate, and the first transfer rate is greater than 200million micro-LEDs/hour.

Optionally, the first transferring process for transferring the microlight emitting diodes passing the test to the permanent substrate has afirst transfer rate, and the first transfer rate is greater than 500million micro-LEDs/hour.

The first selectively removing process for removing the abnormal microlight emitting diodes has a first removal rate, and the first removalrate is greater than 1 million micro-LEDs/hour.

Optionally, the first selectively removing process for removing theabnormal micro light emitting diodes has a first removal rate, and thefirst removal rate is greater than 10 million micro-LEDs/hour.

Optionally, the first selectively removing process for removing theabnormal micro light emitting diodes has a first removal rate, and thefirst removal rate is greater than 20 million micro-LEDs/hour.

Optionally, the first selectively removing process for removing theabnormal micro light emitting diodes has a first removal rate, and thefirst removal rate is greater than 100 million micro-LEDs/hour.

Optionally, the first selectively removing process for removing theabnormal micro light emitting diodes has a first removal rate, and thefirst removal rate is greater than 200 million micro-LEDs/hour.

Optionally, the first selectively removing process for removing theabnormal micro light emitting diodes has a first removal rate, and thefirst removal rate is greater than 500 million micro-LEDs/hour.

The second transferring process for filling the vacancy on the permanentsubstrate has a second transfer rate, and the second transfer rate isgreater than 1 million micro-LEDs/hour.

Optionally, the second transferring process for filling the vacancy onthe permanent substrate has a second transfer rate, and the secondtransfer rate is greater than 10 million micro-LEDs/hour.

Optionally, the second transferring process for filling the vacancy onthe permanent substrate has a second transfer rate, and the secondtransfer rate is greater than 20 million micro-LEDs/hour.

Optionally, the second transferring process for filling the vacancy onthe permanent substrate has a second transfer rate, and the secondtransfer rate is greater than 100 million micro-LEDs/hour.

Optionally, the second transferring process for filling the vacancy onthe permanent substrate has a second transfer rate, and the secondtransfer rate is greater than 200 million micro-LEDs/hour.

Optionally, the second transferring process for filling the vacancy onthe permanent substrate has a second transfer rate, and the secondtransfer rate is greater than 500 million micro-LEDs/hour.

In the above-mentioned fabrication method of the Micro-LED device, thegrowth substrate 100 may for example include materials of silicon,aluminum oxide (Al₂O₃), gallium nitride (GaN), silicon carbide (SiC) andgallium arsenide (GaAs), but not limited thereto.

In the above-mentioned fabrication method of the Micro-LED device, eachof the micro light emitting diodes can be controlled independently.

A further Micro-LED device according to an embodiment of the presentinvention includes a first type semiconductor layer 101, a second typesemiconductor layer 102, a light emitting layer 103 located between thefirst type semiconductor layer 101 and the second type semiconductorlayer 102, a magnetic layer located below the first type semiconductorlayer 101, and a sidewall current limiting area located at the peripherysidewall regions of the second type semiconductor layer 102 and thelight emitting layer 103, wherein the upper surface of the sidewallcurrent limiting area and the upper surface of the second typesemiconductor layer are coplanar, and the periphery perimeter of thefirst current limiting area is less than or equal to 400 micrometers.

The beneficial effects of the above-mentioned Micro-LED device are thatthe micro light emitting diodes have magnetic feature, the sidewallcurrent limiting area can reduce sidewall leakage current, and the lightemitting efficiency of the micro light emitting diode can be improved.

The Micro-LED device may further include a second current limiting area202 surrounded by the sidewall current limiting area, wherein theshortest distance between the sidewall current limiting area and thesecond current limiting area 202 is less than or equal to 50micrometers. The second current limiting area 202 is located in themiddle of the second type semiconductor layer 102. The magnetic layermay include a semiconductor, a conductor layer and an oxide layer, andmay be formed by epitaxial doping, ion implantation, diffusion or thinfilm deposition, wherein the magnetic material in epitaxial doping, ionimplantation, diffusion or thin film deposition may include Fe, Co, Ni,Tb, Al, Pt, Sm, Cu, Cr or the combinations thereof. The light emittinglayer includes single-layer quantum well structure or multi-layerquantum well structure. Optionally, the light emitting layer includessingle-layer quantum wire structure or multi-layer quantum wirestructure. Optionally, the light emitting layer includes single-layerquantum dot structure or multi-layer quantum dot structure. In suchcase, the upper surface of the second type semiconductor layer 102, theupper surface of the sidewall current limiting area and the uppersurface of the second current limiting area 202 are coplanar. The secondcurrent limiting area 202 can be formed by ion implantation technique.

The Micro-LED device may further include a third current limiting area203 located between the sidewall current limiting area and the secondcurrent limiting area 202 and in contact with the second currentlimiting area 202. The Micro-LED device may further include atransparent electrode 301 located above the second type semiconductorlayer 102 and electrically connected to the second type semiconductorlayer 102, and the transparent electrode 301 covers the sidewall currentlimiting area and the third current limiting area 203. The Micro-LEDdevice may further include an electrode 302 located above the secondtype semiconductor layer 102 and electrically connected to thetransparent electrode 301, and the electrode 302 is directly in contactwith the second current limiting area 202. The Micro-LED device mayfurther include an electrode extension part 303 located above thetransparent electrode 301 and electrically connected to the electrode302. The upper surface of the third current limiting area 203 and theupper surface of the sidewall current limiting area are coplanar. Thethird current limiting area 203 is formed by ion implantation technique.The second current limiting area 202 has a second depth D2, the thirdcurrent limiting area 203 has a third depth D3, and the second depth D2is equal to the third depth D3. The Micro-LED device may further includea transparent electrode 301 located above the second type semiconductorlayer 102 and electrically connected to the second type semiconductorlayer 102, and the transparent electrode 301 covers the sidewall currentlimiting area. The transparent electrode has high light transmittanceratio, thereby improving the light emitting efficiency of the microlight emitting diode. The Micro-LED device may further include anelectrode 302 located above the second type semiconductor layer 102 andelectrically connected to the transparent electrode 301, and theelectrode 302 is directly in contact with the second current limitingarea 202, thereby preventing the electrode from peeling and improvingstability of the products. The Micro-LED device may further include anelectrode extension part 303 located above the transparent electrode 301and electrically connected to the electrode 302.

The sidewall current limiting area can be formed through ionimplantation technique, wherein:

(1) The sidewall current limiting area can reduce sidewall leakagecurrent, and the light emitting efficiency of the micro light emittingdiode can be improved.

(2) The second current limiting area 202 can improve the uniformity ofcurrent distribution, and the light emitting efficiency of the microlight emitting diode can be improved.

(3) The third current limiting area 203 can improve the uniformity ofcurrent distribution, and the light emitting efficiency of the microlight emitting diode can be improved.

(4) Ion implantation technique can increase sidewall flatness, and thestability of the products can be improved.

(5) Ion implantation technique can increase surface flatness, and thestability of the products can be improved.

The sidewall current limiting area has a first width T1 greater than orequal to 1 micrometer.

A further Micro-LED device according to an embodiment of the presentinvention includes a first type semiconductor layer 101, a second typesemiconductor layer 102, a light emitting layer 103 located between thefirst type semiconductor layer 101 and the second type semiconductorlayer 102, a magnetic layer located below the first type semiconductorlayer 101 and a first current blocking area 501 located at peripherysidewall regions of the second type semiconductor layer 102 and thelight emitting layer 103, wherein the periphery perimeter of the firstcurrent blocking area 501 is less than or equal to 400 micrometers.

By adopting the above-mentioned structure, the beneficial effects are asfollowing. The micro light emitting diodes have magnetic feature, andthe first current blocking area 501 can reduce sidewall leakage current,thereby improving the light emitting efficiency of the micro lightemitting diode. The periphery perimeter of the first current blockingarea 501 is less than or equal to 400 micrometers, which meets the sizescale of the micro light emitting diode, thereby having variousadvantages of the micro light emitting diode.

The Micro-LED device may further include a second current blocking area502 surrounded by the first current blocking area 501, wherein theshortest distance between the first current blocking area 501 and thesecond current blocking area 502 is less than or equal to 50micrometers. In such case, the Micro-LED device may further include athird current blocking area 503 surrounded by the first current blockingarea 501 and in contact with the second current blocking area 502. TheMicro-LED device may further include a transparent electrode 301 locatedabove the second type semiconductor layer 102 and electrically connectedto the second type semiconductor layer 102, and the transparentelectrode 301 covers the first current blocking area 501, the secondcurrent blocking area 502 and the third current blocking area 503. Thesecond current blocking area 502 has a hollow ring shape and a hollowwidth O2, wherein the hollow width O2 is greater than or equal to 1micrometer. The second current blocking area 502 is located in themiddle of the second type semiconductor 102. The Micro-LED device mayfurther include an electrode 302 located above the second typesemiconductor layer 102 and electrically connected to the transparentelectrode 301, and the electrode 302 is directly in contact with thesecond type semiconductor layer 102. The Micro-LED device may furtherinclude an electrode extension part 303 located above the transparentelectrode 301 and electrically connected to the electrode 302. The widthof the electrode extension part 303 is less than the width of the thirdcurrent blocking area 503. The Micro-LED device further includes atransparent electrode 301 located above the second type semiconductorlayer 102 and electrically connected to the second type semiconductorlayer 102, and the transparent electrode 301 covers the first currentblocking area 501 and the second current blocking area 502. TheMicro-LED device may further include an electrode 302 located above thesecond type semiconductor layer 102 and electrically connected to thetransparent electrode 301, and the electrode 302 is directly in contactwith the second type semiconductor layer 102, thereby preventing theelectrode from peeling and improving the stability of the products. Thetransparent electrode has high light transmittance ratio, therebyimproving the light emitting efficiency of the micro light emittingdiode. The Micro-LED device may further include an electrode extensionpart 303 located above the transparent electrode 301 and electricallyconnected to the electrode 302.

The width T2 of the first current blocking area 501 is greater than orequal to 1 micrometer.

A further Micro-LED device according to an embodiment of the presentinvention includes a first type semiconductor layer 101, a second typesemiconductor layer 102, a light emitting layer 103 located between thefirst type semiconductor layer 101 and the second type semiconductorlayer 102, and a sidewall current limiting area 201 directly in contactwith the periphery sidewall region of the second type semiconductorlayer 102, wherein the sidewall current limiting area 201 furtherincludes an upper surface 201-up, a bottom surface 101-down, an outersurface 201-out and an inner surface 201-in. The second typesemiconductor layer 102 further includes an upper surface 102-up and anouter surface 102-out, and the periphery perimeter of the sidewallcurrent limiting area 201 is less than or equal to 400 micrometers.

By adopting the above-mentioned structure, the beneficial effects are asfollowing:

(1) The sidewall current limiting area 201 can reduce sidewall leakagecurrent, and the light emitting efficiency of the micro light emittingdiode can be improved.

(2) The peripheral perimeter is equal to or less than 400 micrometersand reach the size of micro light emitting diodes, thereby havingvarious advantages of micro light emitting diodes.

The upper surface 102-up of the second type semiconductor layer 102 andthe upper surface 201-up of the sidewall current limiting area 201 arecoplanar.

The Micro-LED device may further include a transparent electrode 301located above the second type semiconductor layer 102 and electricallyconnected to the second type semiconductor layer 102, and thetransparent electrode 301 covers the sidewall current limiting area 201.The Micro-LED device may further include an electrode 302 located abovethe second type semiconductor layer 102 and electrically connected tothe transparent electrode 301, and the electrode 302 is directly incontact with the second type semiconductor layer 102, thereby preventingthe electrode from peeling and improving the stability of the products.The transparent electrode has high light transmittance ratio, therebyimproving the light emitting efficiency of the micro light emittingdiode.

The sidewall current limiting area 201 can be formed through ionimplantation technique. Ion implantation technique can increase sidewallflatness, thereby improving the stability of the products.

The sidewall current limiting area 201 has a first width T1 greater thanor equal to 1 micrometer.

The Micro-LED device may further include a back electrode 304 locatedbelow the first type semiconductor layer and electrically connected tothe first type semiconductor layer.

The upper surface 201-up of the sidewall current limiting area has asurface low conductivity region

_(L-up), the upper surface 102-up of the second type semiconductor layerhas a surface high conductivity region

_(H-up), and a conductivity distribution is gradually increased from thesurface low conductivity region

_(L-up) toward the surface high conductivity region

_(H-up), which helps reduce surface leakage current and sidewall leakagecurrent, and the light emitting efficiency of the micro light emittingdiode can be improved.

The outer surface 201-out of the sidewall current limiting area has asidewall low conductivity region

_(L-out), the outer surface 102-out of the second type semiconductorlayer has a sidewall high conductivity region

_(H-cut), and a conductivity distribution is gradually increased fromthe sidewall low conductivity region

_(L-cut) toward the high conductive region

_(H-out).

The upper surface 201-up of the sidewall current limiting area has afirst surface roughness RS-201-up not greater than 10 nanometers.

The upper surface 102-up of the second type semiconductor layer has asecond surface roughness RS-102-up not greater than 10 nanometers.

Alternatively, the upper surface 201-up of the sidewall current limitingarea has a first surface roughness RS-201-up, the upper surface 102-upof the second type semiconductor layer has a second surface roughnessRS-102-up, and the first surface roughness RS-201-up is greater than orequal to the second surface roughness RS-102-up.

The outer surface 201-out of the sidewall current limiting area has athird surface roughness RS-201-out greater than 10 nanometers.

The outer surface 102-out of the second type semiconductor layer has afourth surface roughness RS-102-out greater than 10 nanometers.

Optionally, the outer surface 201-out of the sidewall current limitingarea has a third surface roughness RS-201-out, the outer surface 102-outof the second type semiconductor layer has a fourth surface roughnessRS-102-out, and the third surface roughness RS-201-out is greater thanor equal to the fourth surface roughness RS-102-out.

Optionally, the upper surface 201-up of the sidewall current limitingarea has a first surface roughness RS-201-up, the outer surface 201-outof the sidewall current limiting area has a third surface roughnessRS-201-out, and the first surface roughness RS-201-up is greater than orequal to the third surface roughness RS-201-out.

Optionally, the upper surface 102-up of the second type semiconductorlayer has a second surface roughness RS-102-up, the outer surface102-out of the second type semiconductor layer has a fourth surfaceroughness RS-102-out, and the second surface roughness RS-102-up isgreater than or equal to the fourth surface roughness RS-102-out.

The advantage of the above-mentioned optional embodiments includes thatthe leakage current can be reduced by controlling surface roughness andsidewall roughness, thereby improving the light emitting efficiency ofthe micro light emitting diode.

The sidewall current limiting area 201 has a first depth D1 less than 1micrometer. Alternatively, the sidewall current limiting area 201 has afirst depth D1 greater than or equal to 1 micrometer.

The sidewall current limiting area 201 further includes the sidewallregion 103-out of the light emitting layer 103.

The sidewall current limiting area 201 further includes the sidewallregion outside the light emitting layer 103.

The sidewall current limiting area 201 further includes the sidewallregion 103-out of the light emitting layer 103 and the sidewall region101-out of the first type semiconductor layer 101.

The advantage of the above-mentioned optional embodiments includes thata preferable effect of reducing sidewall leakage current can be achievedby controlling the depth of the sidewall current limiting area, therebyimproving the light emitting efficiency of the micro light emittingdiode.

Optionally, the upper surface 201-up of the sidewall current limitingarea and the outer surface 201-out of the sidewall current limiting areahave a first included angle Θ1, and the upper surface 201-up of thesidewall current limiting area and the inner surface 201-in of thesidewall current limiting area have a second included angle Θ2. Thefirst included angle Θ1 is an acute angle which is less than 90 degrees,and the second included angle Θ2 is an obtuse angle which is greaterthan 90 degrees.

Optionally, the upper surface 201-up of the sidewall current limitingarea and the outer surface 201-out of the sidewall current limiting areahave a first included angle Θ1, and the upper surface 201-up of thesidewall current limiting area and the inner surface 201-in of thesidewall current limiting area have a second included angle Θ2. Thefirst included angle Θ1 is an obtuse angle which is greater than 90degrees, and the second included angle Θ2 is an acute angle which isless than 90 degrees.

Optionally, the upper surface 201-up of the sidewall current limitingarea and the outer surface 201-out of the sidewall current limiting areahave a first included angle Θ1, the upper surface 201-up of the sidewallcurrent limiting area and the inner surface 201-in of the sidewallcurrent limiting area have a second included angle Θ2, and the firstincluded angle Θ1 and the second included angle Θ2 are close to rightangle (90°).

Optionally, the upper surface 201-up of the sidewall current limitingarea and the outer surface 201-out of the sidewall current limiting areahave a first included angle Θ1, the upper surface 201-up of the sidewallcurrent limiting area and the inner surface 201-in of the sidewallcurrent limiting area have a second included angle Θ2, and the firstincluded angle Θ1 and the second included angle Θ2 are right angles(90°).

Optionally, the upper surface 201-up of the sidewall current limitingarea and the outer surface 201-out of the sidewall current limiting areahave a first included angle Θ1, the upper surface 201-up of the sidewallcurrent limiting area and the inner surface 201-in of the sidewallcurrent limiting area have a second included angle Θ2, and the firstincluded angle Θ1 and the second included angle Θ2 are obtuse angleswhich are greater than 90 degrees.

Optionally, the upper surface 201-up of the sidewall current limitingarea and the outer surface 201-out of the sidewall current limiting areahave a first included angle Θ1, the upper surface 201-up of the sidewallcurrent limiting area and the inner surface 201-in of the sidewallcurrent limiting area have a second included angle Θ2, and the firstincluded angle Θ1 and the second included angle Θ2 are acute angleswhich are less than 90 degrees.

A further Micro-LED device according to an embodiment of the presentinvention includes a first type semiconductor layer 101, a second typesemiconductor layer 102, a light emitting layer 103 located between thefirst type semiconductor layer 101 and the second type semiconductorlayer 102 and a first current blocking area 501 located at a peripheryof the second type semiconductor layer 102 and on the sidewall region ofthe second type semiconductor layer 102, wherein a peripheral perimeterof the first current blocking area 501 is less than or equal to 400micrometers.

By adopting the above-mentioned structure, the beneficial effects can beas following:

(1) The first current blocking region 501 can reduce sidewall leakagecurrent and improve the light emitting efficiency of the micro lightemitting diode.

(2) The distance of the peripheral perimeter is less than or equal to400 μm, which reaches the size scale of micro light emitting diode, thushaving various advantages thereof.

The first current blocking region 501 at least covers the sidewall ofthe first type semiconductor layer 101, the sidewall of the second typesemiconductor layer 102, and the sidewall of the light emitting layer103. Other options are as following:

The first current blocking region 501 only covers the sidewall of thesecond type semiconductor layer 102 and the sidewall of the lightemitting layer 103.

The first current blocking region 501 only completely covers thesidewall of the second type semiconductor layer 102.

The first current blocking region 501 partially covers the sidewall ofthe second type semiconductor layer 102.

The first current blocking region 501 completely covers the sidewall ofthe light emitting layer 103.

The first current blocking region 501 partially covers the sidewall ofthe light emitting layer 103.

The first current blocking region 501 completely covers the sidewall ofthe first type semiconductor layer 101.

The first current blocking region 501 partially covers the sidewall ofthe first type semiconductor layer 101.

In the above-mentioned device(s), by controlling the depth and range ofthe first current blocking region 501, a preferable effect of reducingsidewall leakage current can be achieved and the light emittingefficiency of the micro light emitting diode can be improved.

The Micro-LED device may further include a transparent electrode 301located above the second type semiconductor layer 102 and electricallyconnected to the second type semiconductor layer 102, and thetransparent electrode 301 covers the first current blocking region 501.In such case, the upper surface 301-up of the transparent electrode 301has an upper-surface high conductivity region

_(H-up), wherein the upper surface 501-up of the first current blockingregion 501 has an upper-surface low conductivity region

_(L-up), and a conductivity distribution is gradually increased from theupper-surface low conductivity region

_(L-up) toward the upper-surface high conductivity region

_(H-up).

The Micro-LED device may further include an electrode 302 located abovethe second type semiconductor layer 102 and electrically connected tothe transparent electrode 301, and the electrode 302 is in directcontact with the second limiting region 202, which can prevent theelectrode from falling off and improve product stability. Thetransparent electrode has high light transmittance ratio, which canimprove the light emitting efficiency of the micro light emitting diode.

The first current blocking area 501 is composed of dielectric material.

The width of the first current blocking area 501 is greater than orequal to 1 micrometer.

The sidewall-covering region of the first current blocking region 501has a thickness H1, and the upper-surface-covering region of the firstcurrent blocking region 501 has a thickness H2, wherein the thickness H1is greater than, less than, or equal to the thickness H2. Thesidewall-covering region of the first current blocking region 501 has anarc corner. By controlling the geometric shape of the first currentblocking region 501, a preferred effect of reducing sidewall leakagecurrent can be achieved and the light emitting efficiency of the microlight emitting diode can be improved.

Regarding the upper surface 501-up and the outer surface 501-out of thefirst current blocking area 501, the options can be as following: theupper surface 501-up of the first current blocking area 501 has a firstsurface roughness RS-501-up not greater than 10 nanometers; the outersurface 501-out of the first current blocking area 501 has a secondsurface roughness RS-501-out not greater than 10 nanometers; the uppersurface 501-up of the first current blocking area 501 has a firstsurface roughness RS-501-up, and the outer surface 501-out of the firstcurrent blocking area 501 has a second surface roughness RS-501-out,wherein the first surface roughness is greater than the second surfaceroughness; the upper surface 501-up of the first current blocking area501 has a first surface roughness RS-501-up, and the outer surface501-out of the first current blocking area 501 has a second surfaceroughness RS-501-out, wherein the first surface roughness is equal tothe second surface roughness; and the upper surface 501-up of the firstcurrent blocking area 501 has a first surface roughness RS-501-up, andthe outer surface 501-out of the first current blocking area 501 has asecond surface roughness RS-501-out, wherein the first surface roughnessis less than the second surface roughness.

In the above-mentioned device(s), leakage current can be reduced bycontrolling the surface roughness and sidewall roughness of the currentblocking area 501, and the light emitting efficiency of the micro lightemitting diode can be improved.

Optionally, the upper surface 501-up of the first current blocking area501 has a surface low conductivity region

_(L-up), the upper surface 102-up of the second type semiconductor layerhas a surface high conductivity region

_(H-up), and a conductivity distribution is gradually increased from thesurface low conductivity region

_(L-1) toward the surface high conductivity region

_(H-up).

Optionally, the outer surface 501-out of the first current blocking area501 has an outer surface low conductivity region

_(L-out), the upper surface 501-up of the first current blocking area501 has an upper surface low conductivity region

_(L-up), and the conductivity of the outer surface low conductivityregion

_(L-out) is equal to the conductivity of the upper surface lowconductivity region

_(L-up).

Optionally, the outer surface 501-out of the first current blocking area501 has an outer surface low conductivity region

_(L-out), the upper surface 501-up of the first current blocking area501 has an upper surface low conductivity region

_(L-up), and the conductivity of the outer surface low conductivityregion

_(L-out) is greater than the conductivity of the upper surface lowconductivity region

_(L-up).

Optionally, the outer surface 501-out of the first current blocking area501 has an outer surface low conductivity region

_(L-out), the upper surface 501-up of the first current blocking area501 has an upper surface low conductivity region

_(L-up), and the conductivity of the outer surface low conductivityregion

_(L-out) is less than the conductivity of the upper surface lowconductivity region

_(L-up).

In the above-mentioned device(s), surface leakage current and sidewallleakage current can be reduced, and the light emitting efficiency of themicro light emitting diode can be improved.

An embodiment of the present invention further includes a display panel.The display panel includes a display substrate, and the displaysubstrate includes an array of the Micro-LED devices, wherein a portionof the Micro-LED devices have sidewall current blocking areas 501, and aportion of the Micro-LED devices have sidewall current limiting areas201.

Regarding the formation of the sidewall current blocking area, theoptions can be as following:

The sidewall current blocking area 501 can be formed through atomiclayer chemical vapor deposition system (ALD) technique.

The sidewall current blocking area 501 can be formed through metalorganic chemical vapor phase deposition (MOCVD) epitaxial regrowthtechnique.

The sidewall current blocking area 501 can be formed through molecularbeam epitaxy (MBE) of epitaxial regrowth technique.

The sidewall current blocking area 501 can be formed through plasmaenhanced chemical vapor deposition (PECVD) technique.

The sidewall current limiting area 201 can be formed through selectiveoxidation technique.

The sidewall current limiting area 201 can be formed through thermaloxidation technique.

The sidewall current limiting area 201 can be formed through wet thermaloxidation technique.

The sidewall current limiting area can be formed through ionimplantation technique.

The maximum width of each of the Micro-LED devices is in a range from 1micrometer to 100 micrometers.

Each of the Micro-LED devices includes a semiconductor material.

Each of the Micro-LED devices includes a first type semiconductor layer101, a second type semiconductor layer 102 and a light emitting layer103 located between the first type semiconductor layer 101 and thesecond type semiconductor layer 102.

The above-mentioned display panel further includes a circuit used toswitch and drive the array of the Micro-LED devices and an array ofmicrocontroller chips. In addition, each of the microcontroller chips isconnected to a scan driving circuit and a data driving circuit.

An embodiment of the present invention further provides a flexibledisplay including a flexible substrate 1010, and the flexible substratefurther includes an array of the Micro-LED devices, wherein a portion ofthe Micro-LED devices have sidewall current blocking areas 501, and aportion of the Micro-LED devices have sidewall current limiting areas201.

Optionally, the sidewall current blocking area 501 is composed ofdielectric material.

Optionally, the sidewall current limiting area is formed by ionimplantation technique.

The maximum width of each of the Micro-LED devices is in a range from 1micrometer to 100 micrometers.

Each of the Micro-LED devices includes a semiconductor material.

Each of the Micro-LED devices includes a first type semiconductor layer101, a second type semiconductor layer 102 and a light emitting layer103 located between the first type semiconductor layer 101 and thesecond type semiconductor layer 102.

The flexible display may further include a circuit used to switch anddrive the array of the Micro-LED devices and an array of microcontrollerchips. Each of the microcontroller chips is connected to a scan drivingcircuit and a data driving circuit. The flexible substrate 1010 mayfurther include a plurality of data lines 1015, wherein each of themicro-LED devices 1011 is electrically connected to a corresponding scanline 1014 and a corresponding data line 1015; a driving circuit used fordriving the array of the micro-LED devices, wherein the driving circuitincludes a gate driver 1012 and a source driver 1013.

Material of the flexible substrate may include ultra-thin glass, metalfoil, fiber-reinforced composite material, plastic film, ceramicsubstrate or the combinations of any two or more of the above-mentionedmaterials. The thickness of the flexible substrate is preferable lessthan 200 micrometers, more preferable less than 50 micrometers, and evenmore preferable in a range from 25 micrometers to 50 micrometers. Metalfoil may for example include stainless steel, aluminum, nickel,titanium, zirconium, copper, iron, cobalt, palladium or the combinationsof any two or more of the above-mentioned materials. Wherein, thecoefficient of thermal expansion of the metal foil is similar to thecoefficient of thermal expansion of ultra-thin glass. The surfaceroughness Ra of the metal foil is less than 10 nanometers. The lighttransmittance of the plastic film is greater than 90% under a wavelengthof 550 nanometer. The material of the plastic film may for exampleinclude polyethylene terephthalate (PET), polyethylene naphthalate (PEN)or polyethersulfone (PES). The fiber-reinforced composite material mayfor example include carbon fibers, silicon carbide fibers or boronfilament.

According to even further aspect of the present invention, a flexibledisplay including an array composed of the diode devices of the presentinvention is provided.

An embodiment of the present invention further provides a fabricationmethod of the flexible display, the fabrication method includes:providing a flexible substrate; disposing a plurality of scan lines,wherein the scan lines are disposed on the flexible substrate parallelto a first direction; disposing a plurality of data lines, wherein thedata lines are disposed on the flexible substrate parallel to a seconddirection, wherein the first direction is perpendicular to the seconddirection; and disposing a plurality of micro light emitting diodearrays, wherein each of the micro light emitting diodes is electricallyconnected to a corresponding data line, and each of the micro lightemitting diodes is electrically connected to a corresponding scan line.

A portion of the Micro-LED devices have sidewall current blocking area501 s, and a portion of the Micro-LED devices have sidewall currentlimiting areas 201.

The Micro-LED device achieved by 3D stacking of arrays of RGB pixels isprovided by another embodiment of the present invention, and yields ofmassive transfer can be improved by ion implantation planarizationtechnique. The spare LEDs can be disposed in the sub-pixel according tothe technique of 3D stacking of arrays of RGB pixels, thus theproduction cost for exchanging the broken spot can be prevented.Besides, by shrinking the distance of the sub-pixels, the broken spotmay not be easily detected by human eyes because the distance of thesub-pixels is less than the minimum resolution of human eyes, that is,technique of exchanging the broken spot is not needed. Furthermore, themicro-LED can be achieved through transmissive epitaxial substratecombined with 3D stacking of arrays of RGB pixels, and the technique ofdirectly forming the epitaxial chip in the micro-LED display can beachieved, in which massive transfer technique is not needed.

Conventionally, a flip-chip micro LED structure is shown in FIG. 29, thesize of the micro LED is that the side length of the micro LED is lessthan 100 micrometers. The side length ranged from 10 micrometers to 100micrometers can be achieved by conventional manufacturing manners.

When the size is shrunk to be less than 10 micrometers, as shown in FIG.30, the micro-LED components with smaller pitch can be defined byetching (such as dry etching or wet etching) or cutting, however, thedangling bond (that is, the electrons not bonded) may be easily formedon the surface and sidewall of the components. The dangling bondcontains extremely high activity, which can form trap centers easily andcause re-bonding of electron-hole pairs, thereby reducing lifespan ofthe carrier and reducing transfer efficiency, thereby increasing theratio of leakage current to total current in the micro-LED, and thelight emitting efficiency of the micro-LED may be reduced. The surfaceroughness and sidewall roughness of the components can be reduced by ionimplantation technique in the present invention, thereby reducing thenon-radiative recombination of the micro-LED, and the efficiency of themicro-LED can be improved.

As shown in FIG. 30, when the size is shrunk to be less than 10micrometers, the ridge area is easily broken during etching, especiallyduring flip chip process or massive transfer. Besides, because the metalbump is not flat, it would be broken during massive transfer, andproduction yields would be reduced.

As shown in FIG. 31, the size of the flip chip micro LED is shrunk byion implantation technique, and because the surface flatness isincreased, problems like broken of the etched ridge area or unflat ofmetal bump can be solved, and production yields can be improved.

As shown in FIG. 32, at least one spare LED is disposed in the structureby ion implantation technique to prevent extra cost for exchanging thebroken spot.

AS shown in FIG. 33-1, a first epitaxial layer structure (Epi layer-1)is formed on the first epitaxial substrate S1, and a first micro-LED M1with the pitch P1 is formed by photolithography and etching process.FIG. 33-2 schematically illustrates a horizontal cross-sectional viewalong line A-A′ in the top view of FIG. 33-3.

As shown in FIG. 34-1 and FIG. 34-2, the first ion implantation areaIon-1 and the first sub-pixel area R1 can be defined on the firstmicro-LEDs M1 by ion implantation technique.

As shown in FIG. 35-1, FIG. 35-2 and FIG. 35-3, a conductive layer ML isformed above the first sub-pixel area R1. FIG. 35-1 and FIG. 35-2schematically illustrates a horizontal cross-sectional view along lineA-A′ and line A′-A′″ in FIG. 35-3 respectively.

AS shown in FIG. 36-1, the first sub-pixels R1 including the conductivelayer ML are electrically connected to the first transparent substrateT1 through a bonding pad respectively, and the first epitaxial substrateS1 is removed by etching or laser, as shown in FIG. 36-2. Then, a firstlight-transmissive intermediate layer B1 is filled between the firsttransparent substrate T1 and the first sub-pixels R1 to strengthen themechanical structure, wherein the first micro-LEDs M1 located on thefirst transparent substrate T1 has a pitch P2, and the pitch P1 is equalto pitch P2. FIG. 36-2 schematically illustrates a first sub-pixel arraystructure.

As shown in FIG. 37-1, a second epitaxial layer structure (Epi layer-2)is formed on the second epitaxial substrate S2, and second micro-LEDs M2with a pitch P3 are formed by photolithography and etching process. FIG.37-2 schematically illustrates a horizontal cross-sectional view alongline C-C′ in the top view of FIG. 37-3.

As shown in FIG. 38-1 and FIG. 38-2, a first region Ion-2 a of thesecond ion implantation area, a second region Ion-2 b of the second ionimplantation area and a second sub-pixel area G1 can be defined on eachof the second micro-LEDs M2 by ion implantation technique.

As shown in FIG. 39-1, FIG. 39-2 and FIG. 39-3, a conductive layer ML isformed above the second sub-pixel area G1. FIG. 39-1 and FIG. 39-2schematically illustrate a horizontal cross-sectional view along lineC-C′ and line C′-C′″ in FIG. 39-3 respectively.

As shown in FIG. 40-1, the second sub-pixel area G1 including conductivelayer ML is electrically connected to a second transparent substrate T2through a bonding pad respectively, and the second epitaxial substrateS2 is removed by etching or laser, as shown in FIG. 40-2. Then, a secondlight-transmissive intermediate layer B2 is filled between the secondtransparent substrate T2 and the second sub-pixels G1 to strengthen themechanical structure, wherein the second micro light emitting diodes M2located in the second transparent substrate T2 has a second pitch P4,and the pitch P3 is equal to the second pitch P4. FIG. 40-2schematically illustrates a second sub-pixel array structure.

As shown in FIG. 41-1, a third epitaxial layer structure (Epi layer-3)is formed on the third epitaxial substrate S3, and third micro-LEDs M3with a pitch P5 are formed by photolithography and etching process. FIG.41-2 schematically illustrates a horizontal cross-sectional view alongline C-C′ in the top view shown in FIG. 41-3.

As shown in FIG. 42-1 and FIG. 42-2, the third ion implantation areaIon-3 and the third sub-pixel area B1 can be defined on the thirdmicro-LEDs M3 by ion implantation technique.

As shown in FIG. 43-1, FIG. 43-2 and FIG. 43-3, a conductive layer ML isformed above the third sub-pixel area B1. FIG. 43-1 and FIG. 43-2schematically illustrate a horizontal cross-sectional view along lineE-E′ and line E′-E′″ in the top view of FIG. 43-3 respectively.

As shown in FIG. 44-1, the third sub-pixel area B1 including conductivelayer ML is electrically connected to a third transparent substrate T3through a bonding pad, and the third epitaxial substrate S3 is removedby etching or laser, as shown in FIG. 44-2. Then, a thirdlight-transmissive intermediate layer B3 is filled between the thirdtransparent substrate T3 and the third sub-pixel B1 to strengthen themechanical structure, wherein the third micro-LEDs M3 located in thethird transparent substrate T3 have a pitch P6, and the pitch P5 isequal to the pitch P6. FIG. 44-2 schematically illustrates a thirdsub-pixel array structure, wherein the pitch P2 is equal to the pitch P4and equal to the pitch P6.

FIG. 45-1 and FIG. 45-2 schematically illustrates stacking a firstsub-pixel structure, a second sub-pixel structure, and a third sub-pixelstructure by light-transmissive adhesive layers (A-1 and A-2) to form athree-dimensional (3-D) stack of RGB pixels array, thereby achieving themicro LED, wherein FIG. 45-2 schematically illustrates an enlargementview of the first pixel (pixel 1) and a horizontal cross-sectional viewalong line G-G′ in FIG. 45-3. The first sub-pixel area R1 is equal tothe first region Ion-2 a of the second ion implantation area, the thirdsub-pixel area B1 is equal to the second region Ion-2 b of the secondion implantation area, and the second sub-pixel area G1 plus the thirdsub-pixel area B1 are equal to the first ion implantation area Ion-1.The Micro-LED achieved by 3D stacking of RGB pixels arrays according tothe present invention has a thickness D-1, wherein the thickness D-1 isless than 500 micrometers in an embodiment, the thickness D-1 is lessthan 200 micrometers in a preferable embodiment, the thickness D-1 isless than 100 micrometers in a more preferable embodiment, and thethickness D-1 is less than 50 micrometers in an even more preferableembodiment. In an embodiment, the sub-pixel with the longest wavelengthis located at the bottom, and the sub-pixel with the shortest wavelengthis located at the top, thereby preventing the sub-pixel with shortwavelength from exciting the sub-pixel with a long wavelength, but thewavelength range of the light of the sub-pixels is not limited thereto.The Micro-LED is achieved by 3D stacking of RGB pixels arrays, whereinthe light transmittance of the Micro-LED is greater than 60% in anembodiment, the light transmittance of the Micro-LED is greater than 70%in a preferable embodiment, the light transmittance of the Micro-LED isgreater than 80% in a more preferable embodiment, and the lighttransmittance of the Micro-LED is greater than 90% in an even morepreferable embodiment.

The transparent substrate T1,T2 and T3 of the present invention may be aflexible substrate, wherein the material of the flexible substrate mayinclude ultra-thin glass, metal foil, fiber-reinforced compositematerial, plastic film, ceramic substrate or the combinations thereof,wherein a preferable thickness of the flexible substrate is less than200 micrometers, a more preferable thickness of the flexible substrateis less than 50 micrometers, and an even more preferable thickness ofthe flexible substrate is in a range from 25 micrometers to 50micrometers.

The coefficient of thermal expansion of the metal foil is similar to thecoefficient of thermal expansion of the ultra-thin glass. The surfaceroughness Ra of the transparent metal foil is less than 10 nanometers.The light transmittance of the plastic film is greater than 90% under awavelength of 550 nanometer. The material of the plastic film may forexample include polyethylene terephthalate (PET), polyethylenenaphthalate (PEN) or polyethersulfone (PES). The fiber-reinforcedcomposite material may for example include carbon fibers, siliconcarbide fibers or boron filament.

In another embodiment of the present invention shown in FIG. 46-1 andFIG. 46-2, R1-1 is the first sub-pixel, R1-2 is the first sparesub-pixel, G1-1 is the second sub-pixel, G1-2 is the second sparesub-pixel, B1-1 is the third sub-pixel, and B1-2 is the third sparesub-pixel. By controlling the sub-pixels through the circuit, only oneof the sub-pixels R1-1 and R1-2 can emit light, only one of thesub-pixels G1-1 and G1-2 can emit light, and only one of the sub-pixelsB1-1 and B1-2 can emit light. Besides, the first sub-pixel (R1-1) areaplus the first spare sub-pixel (R1-2) area are equal to the first regionIon-2 a of the second ion implantation area, the third sub-pixel (B1-1)area plus the third spare sub-pixel (B1-2) area are equal to the secondregion Ion-2 b of the second ion implantation area, and the secondsub-pixel (G1-1) area plus the second spare sub-pixel area (G1-2), thethird sub-pixel (B1-1) area and the third spare sub-pixel (B1-2) areaare equal to the first ion implantation area Ion-1.

(R1-1)+(R1-2)=Ion-2a

(B1-1)+(B1-2)=Ion-2b

(G-1)+(G1-2)+(B1-1)+(B1-2)=Ion-1

In another embodiment of the present invention shown in FIG. 47-1 andFIG. 47-2, R1-1 is the first sub-pixel, R1-2, R1-3, R1-4, R1-5 and R1-6are the first spare sub-pixels, G1-1 is the second sub-pixel, G1-2, G1-3and G1-4 are the second spare sub-pixels, B1-1 is the third sub-pixel,and B1-2 is the third spare sub-pixel. By controlling the sub-pixels bythe circuit, only one of the sub-pixels R1-1, R1-2, R1-3, R1-4, R1-5 andR1-6 can emit light, only one of the sub-pixels G1-1, G1-2, G1-3 andG1-4 can emit light, and only one of the sub-pixels B1-1 and B1-2 canemit light. The advantages of the design include that the usage of thespare sub-pixels is more flexible.

The first sub-pixel (R1-1) area plus the first spare sub-pixel (R1-2)area is equal to the second ion implantation area Ion-2.

(R-1)+(R1-2)=Ion-2

(R-3)+(R1-4)=(G1-1)+(G1-2)

(R1-5)+(R1-6)=(G1-3)+(G1-4)=(B1-1)+(B1-2)

(R-1)+(R1-2)+(R1-3)+(R1-4)=Ion-3

In another embodiment of the present invention shown in FIG. 48-1 andFIG. 48-2, R1-1 is the first sub-pixel, R1-2, R1-3, R1-4, R1-5 and R1-6are first spare sub-pixels, G1-1 is the second sub-pixel, G1-2, G1-3,G1-4, G1-5 and G1-6 are second spare sub-pixels, B1-1 is the thirdsub-pixel, B1-2, B1-3, B1-4, B1-5 and B1-6 are third spare sub-pixels.By controlling the sub-pixels by the circuit, only one of the sub-pixelsR1-1, R1-2, R1-3, R1-4, R1-5 and R1-6 can emit light, only one of thesub-pixels G1-1, G1-2, G1-3, G1-4, G1-5 and G1-6 can emit light, andonly one of the sub-pixels B1-1, B1-2, B1-3, B1-4, B1-5 and B1-6 canemit light. The advantages of the design include that the usage of thespare sub-pixels is more flexible. The relations between differentsub-pixel areas are shown below:

(R1-1)=(G1-5)=(B1-3)

(R1-2)=(G1-6)=(B1-4)

(R1-3)=(G1-1)=(B1-5)

(R1-4)=(G1-2)=(B1-6)

(R1-5)=(G1-3)=(B1-1)

(R1-6)=(G1-4)=(B1-2)

In another embodiment of the present invention shown in FIG. 49-1 andFIG. 49-2, R1-1A, R1-2A, R1-3A, R1-4A, R1-5A and R1-6A are the firstsub-pixels, G1-1A, G1-2A, G1-3A, G1-4A, G1-5A and G1-6A are the secondsub-pixels, B1-1A, B1-2A, B1-3A, B1-4A, B1-5A and B1-6A are the thirdsub-pixels.

Pixel 1 is composed of pixel 1A to pixel 1F, because the width of anyone of the pixel 1A to pixel 1F is less than the resolution of humaneyes, spare pixel is not necessary. Because human eyes cannot recognizethe broken dots when one of the pixel 1A to pixel 1F is broken, exchangeof the broken dot is not necessary. According to an embodiment of thepresent invention, the resolution of the monitor may for example be1440×960 (pixels), the pixel number per inch is 494.48 ppi (pixels perinch), and the dot pitch of the sub-pixels is less than 0.0514micrometers, which is enough to make it impossible for human eyes torecognize the broken dots of a single pixel at normal viewing distance,such that the spare pixel is not necessary. In a preferable embodimentof the present invention, the resolution of the monitor is 1920×1280(pixels), the pixel number per inch is 659.3 ppi, and the dot pitch ofthe sub-pixels is less than 0.0385 micrometers, which is enough to makeit impossible for human eyes to recognize the broken dots of a singlepixel at normal viewing distance, such that the spare pixel is notnecessary even if any adjacent one of the micro light emitting diodes isout of order. In a better embodiment of the present invention, theresolution of the monitor is 3840×2560 (pixels), the pixel number perinch is 1318.6 ppi, and the dot pitch of the sub-pixels is less than0.0193 micrometers, which is enough to make it impossible for human eyesto recognize the broken dots of a single pixel at normal viewingdistance, such that the spare pixel is not necessary even if anyadjacent two of the micro light emitting diodes are out of order.

According to another embodiment of the present invention shown in FIG.50, the epitaxial substrate S1, S2 and S3 are transparent substrates,that is, the micro LED can be formed through 3D stacking of RGB pixelswithout transfer to a transparent substrate, thereby simplifying theprocess.

According to an embodiment of the present invention shown in FIG. 51, ablack mattress layer BM is further included to increase the contrast ofthe pixels.

According to another embodiment of the present invention shown in FIG.52, each of the micro light emitting diodes further includes a magneticlayer ML to improve the precision of 3D stacking, wherein the magneticlayer can be formed through doping, ion implantation, diffusion or thinfilm deposition, and the magnetic material may for example include Fe,Co, Ni, Tb, Al, Pt, Sm, Cu, Cr or the combinations thereof.

According to another embodiment of the present invention shown in FIG.53, each of the micro light emitting diodes further includes a currentblocking area located on the surface and at the sidewall region of themicro light emitting diodes, the current blocking area can reduce thenon-radiative recombination of the micro light emitting diodes, therebyimproving the efficiency of the micro light emitting diodes. The currentblocking area is composed of dielectric material such as siliconnitride, silicon dioxide or aluminum oxide (Al₂O₃), and thesidewall-covering region of the current blocking area of the presentinvention has an arc.

According to another embodiment of the present invention shown in FIG.54, each of the micro light emitting diodes further includes a currentlimiting area located on the surface and at the sidewall region of themicro light emitting diodes, the current limiting area can reduce thenon-radiative recombination of the micro light emitting diodes, therebyimproving the efficiency of the micro light emitting diodes. The currentlimiting area can be formed through formed through ion implantationtechnique.

According to another embodiment of the present invention shown in FIG.55-1, light emitting of the micro light emitting diodes can becontrolled by electrically connecting an integrated control system tothe micro-LED display, and the image displayed by the micro-LED displaycan be projected to an optical component through a lens system andreflected to human eyes. Human eyes can see an augmented reality (AR)formed by actual scene and the images produced by the micro-LED displaythrough the optical component, wherein the optical component can be atransmissive windshield glass, a transparent resin glass, a transmissiveeyeglasses lens or a foldable display which has light transmission andreflection function. The Micro-LED in the micro-LED display can beachieved by 3D stacking of RGB pixels arrays combined with ionimplantation planarization technique. The preferable side length of theMicro-LED is less than 4 micrometers in the present invention.

FIG. 55-2 illustrates another embodiment of the present invention, oneof the difference between this embodiment and the embodiment shown inFIG. 55-1 is that the RGB micro-LED display can be controlledindependently by respectively electrically connecting the integratedcontrol system and the RGB micro-LED display. Since the RGB micro-LEDdisplay can be controlled independently to display images by projection,massive transfer is not necessary, and the RGB micro-LED display can beformed in a single epitaxial chip. The Micro-LED in the micro-LEDdisplay can be achieved by 3D stacking of RGB pixels arrays combinedwith ion implantation planarization technique. The preferable sidelength of the Micro-LED is less than 4 micrometers in the presentinvention.

According to another embodiment of the present invention shown in FIG.55-3, the micro-LED display and the lens system are integrated into anoptical component, the images of the micro-LED display is projected tothe lens system and reflected to human eyes by electrically connectingan integrated control system and the micro-LED display. Human eyes cansee an augmented reality (AR) formed by actual scene and the imagesproduced by the micro-LED display through the optical component, whereinthe optical component can be a transmissive windshield glass, atransparent resin glass, a transmissive eyeglasses lens or a foldabledisplay. The integrated control system can be disposed inside or outsidethe optical component. The Micro-LED in the micro-LED display can beachieved by 3D stacking of RGB pixels arrays combined with ionimplantation planarization technique. The preferable side length of theMicro-LED is less than 4 micrometers in the present invention.

According to another embodiment of the present invention shown in FIG.55-4, one of the difference between this embodiment and the embodimentshown in FIG. 55-3 is that the RGB micro-LED display can be controlledindependently by respectively electrically connecting the integratedcontrol system and the RGB micro-LED display, and the RGB micro-LEDdisplay can controlled independently and display image by projection,thus massive transfer is not necessary and the RGB micro-LED display canbe achieved in a single epitaxial chip. The integrated control systemcan be disposed inside or outside the optical component. The Micro-LEDin the micro-LED display can be achieved by 3D stacking of RGB pixelsarrays combined with ion implantation planarization technique. Thepreferable side length of the Micro-LED is less than 4 micrometers inthe present invention.

As shown in FIG. 55-5, the above-mentioned integrated control systemfurther includes a multi-function sensor, microchip processors, anetwork interface to make the user capable of controlling the micro-LEDdisplay and provide an appropriate augmented reality, wherein themulti-function sensor may for example include ultrasonic sensor, thermalsensor, humidity sensor, gas sensor, pressure sensor, accelerationsensor, ultraviolet light sensor, magnetic-sensitive sensor,magnetic-resistive sensor, image sensor, electricity sensor,displacement sensor, touch sensor, infrared proximity/distance sensor,global positioning system module, gyroscope, accelerometer, fingerprintsensor, iris sensor, button, knob, switch, microphone, camera or RFIDreader module. User can adjust or zoom in/zoom out the position and sizeof the augmented reality by the multi-function sensor, and theappropriate information of the augmented reality can be provided. In anembodiment, the position of the projection of the augmented reality canbe adjusted by sensing the position and status of the pupil through themulti-function sensor cooperating with the microchip processors to makesure the actual scene perceived by human eyes through the opticalcomponent can fit the augmented reality, thereby preventing distortionof the augmented reality, and precise display can be achieved. Besides,data can be transferred to another network by cooperating with thenetwork interface to provide appropriate information of the augmentedreality.

A smart glass structure is shown in FIG. 56-1. An integrated controlsystem and a display are disposed on a frame. An image is projected toan optical component by the display and reflected to human eyes. Humaneyes can see an augmented reality formed by actual scene and the imagesproduced by the micro-LED display through the optical component. Thesmart glass structure is limited to the size of light source, so itcan't achieve the advantages such as thinness and shortness. Thetechniques of the display may be substantially divided into digitallight processing (DLP), microelectromechanical system (MEMS) laser,liquid crystal on silicon (LCOS), etc., wherein the DLP technique is adigital micro-mirror device (DMD) based on a microelectromechanicalsystem component. The volume of the complex periphery circuit of the DMDis greater, and switching of the MEMS component in high frequency alsocauses the problem of excessive power consumption. Besides, thedisadvantages of LCOS technique include low light emitting efficiencyand large volume. The present invention replaces the normal display withthe micro-LED display, which not only improves the resolution, but alsoshrinks the size of the device to fit the size of wearable device(s).Therefore, competitiveness in the market can be improved because of theadvantages like low power consumption and smaller size. Besides, thenormal smart glass is limited to the size of the light source of thedisplay and the design of reflective mirror, so the provided range ofthe augmented reality is also limited. Because the size of the displayis shrunk in the present invention, the design of light path of theprojection is more flexible, a wider range of the augmented reality canbe provided, and a more comfortable environment when using the devicecan be provided. The Micro-LED in the micro-LED display can be achievedby 3D stacking of RGB pixels arrays combined with ion implantationplanarization technique. The preferable side length of the Micro-LED isless than 4 micrometers in the present invention.

An embodiment of the present invention is shown in FIG. 56-2. Anintegrated control system combined with the display is disposed on aframe, an image is projected to an optical component by the display andreflected to human eyes. Human eyes can see an augmented reality formedby actual scene and the images produced by the micro-LED display throughthe optical component.

An embodiment of the present invention is shown in FIG. 56-3. Anintegrated control system combined with the micro-LED display isdisposed at the top of the rims, and an image is projected to an opticalcomponent by the display and reflected to human eyes. Human eyes can seean augmented reality formed by actual scene and the images produced bythe micro-LED display through the optical component.

An embodiment of the present invention is shown in FIG. 56-4. Anintegrated control system combined with the micro-LED display isdisposed at any periphery position of the rims or disposed in the bridgeconnecting the rims which makes the combined structure not limited tothe shape of the rims, and an image is projected to an optical componentby the display and reflected to human eyes. Human eyes can see anaugmented reality formed by actual scene and the images produced by themicro-LED display through the optical component.

An embodiment of the present invention is shown in FIG. 56-5. Anintegrated control system is disposed at the top of the rims, and themicro-LED display and the lens system are integrated into an opticalcomponent. The image of the micro-LED display can be projected to thelens system by electrically connecting the integrated control system andthe micro-LED display and reflected to human eyes. Human eyes can see anaugmented reality formed by actual scene and the images produced by themicro-LED display through the optical component.

Another embodiment of the present invention is shown in FIG. 57-1,wherein the micro LED structure in this embodiment has a magnetic layer.First, an epitaxial substrate is provided, and then, the magnetic layerML is formed above the epitaxial substrate, wherein the material of themagnetic layer may include a semiconductor layer, a conductive layer andan oxide layer, and the magnetic layer can be formed through doping, ionimplantation, diffusion, thin film deposition. The magnetic materialformed by doping, ion implantation, diffusion or thin film depositionmay include Fe, Co, Ni, Tb, Al, Pt, Sm, Cu, Cr or the combinationsthereof. After that, a first type semiconductor layer, a light emittinglayer and a second type semiconductor layer are sequentially formed onthe magnetic layer.

A lateral magnetic micro LED structure is shown in FIG. 57-2. Thelateral magnetic micro LED structure is formed by removing a portion ofthe second type semiconductor layer and the light emitting layer throughetching, exposing a portion of the first type semiconductor layer,forming a metal layer ohm contacted with the first type semiconductorlayer, forming another metal later ohm contacted with the second typesemiconductor layer, and removing the epitaxial substrate.

A vertical magnetic micro LED structure is shown in FIG. 57-3. Thevertical magnetic micro LED structure is formed by forming a metal layerohm contacted with the second type semiconductor layer, exposing themagnetic layer by removing the epitaxial substrate, and forming anothermetal layer ohm contacted with the magnetic layer.

Another vertical magnetic micro-LED structure is shown in FIG. 57-4. Thevertical magnetic micro-LED structure is formed by forming a metal layerohm contacted with the second type semiconductor layer, exposing thefirst type semiconductor layer by removing the epitaxial substrate and aportion of the magnetic layer, and forming another metal layer ohmcontacted with the first type semiconductor layer.

The magnetic micro-LED shown in FIG. 57-5, FIG. 57-6 and FIG. 57-7further includes a first current blocking layer located at the surfaceand sidewall region of the magnetic micro-LED. The first currentblocking layer can reduce the non-radiative recombination of themagnetic micro-LED, thereby improving the efficiency of the micro-LED.The first current blocking layer is composed of dielectric material suchas silicon nitride, silicon dioxide or aluminum oxide (Al₂O₃).

The magnetic micro-LED shown in FIG. 57-8, FIG. 57-9 and FIG. 57-10further includes a first current limiting layer located at the surfaceand sidewall region of the magnetic micro-LED. The first currentlimiting layer can reduce the non-radiative recombination of themagnetic micro-LED, thereby improving the efficiency of the micro-LED.The first current limiting layer is formed through ion implantationtechnique.

A lateral magnetic micro-LED structure is shown in FIG. 57-11. Thelateral magnetic micro-LED structure is formed by removing a portion ofthe second type semiconductor layer and the light emitting layer throughetching, exposing a portion of the first type semiconductor layer,forming a metal layer ohm contacted with the first type semiconductorlayer, forming a second current blocking layer above the second typesemiconductor layer, forming a transparent conductive layer above thesecond type semiconductor layer and in ohm contact with the second typesemiconductor layer, wherein the transparent conductive layer covers thesecond current blocking layer, removing a portion of the transparentconductive layer and the second current blocking layer, exposing aportion of the second type semiconductor layer, forming another metallayer directly in contact with the second type semiconductor layer andelectrically connected to the transparent conductive layer, forming afirst current blocking layer covering the sidewall region and thetransparent conductive layer and removing the epitaxial substrate.

The first current blocking layer can reduce the non-radiativerecombination of the magnetic micro-LED, thereby improving theefficiency of the micro-LED, wherein the first current blocking layer iscomposed of dielectric material. The second current blocking layer canprevent the current crowding effect and improve the effect of currentspreading, thereby increasing the probability of electron-holerecombination, and light emitting efficiency can be improved, whereinthe second current blocking layer is composed of dielectric material.The another metal layer is directly in contact with the second typesemiconductor layer, which gives the effect of stable bonding, and thestability of the structure can be improved.

A lateral magnetic micro-LED structure is shown in FIG. 57-12. Thelateral magnetic micro-LED structure is formed by removing a portion ofthe second type semiconductor layer and the light emitting layer throughetching, exposing a portion of the first type semiconductor layer,forming a metal layer ohm contacted with the first type semiconductorlayer, forming a second current limiting layer at the top region insidethe second type semiconductor layer, forming a transparent conductivelayer above the second type semiconductor layer and in ohm contact withthe second type semiconductor layer, wherein the transparent conductivelayer covers the second current limiting layer, removing a portion ofthe transparent conductive layer, exposing a portion of the second typesemiconductor layer, forming another metal layer directly in contactwith the second type semiconductor layer and electrically connected tothe transparent conductive layer, forming a first current limiting layerat the sidewall region and removing the epitaxial substrate. The firstcurrent limiting layer is located at the surface and sidewall region ofthe magnetic micro-LED. The first current limiting layer can reduce thenon-radiative recombination of the magnetic micro-LED, thereby improvingthe efficiency of the magnetic micro-LED, wherein the first currentlimiting layer can be formed through ion implantation technique. Thesecond current limiting layer can prevent the current crowding effectand improve the effect of current spreading, thereby increasing theprobability of electron-hole recombination, and light emittingefficiency can be improved, wherein the second current limiting layer isformed by ion implantation technique. The another metal layer isdirectly in contact with the second type semiconductor layer, whichgives the effect of stable bonding, and the stability of the structurecan be improved.

A lateral magnetic micro-LED structure is shown in FIG. 57-13. Thelateral magnetic micro-LED structure is formed by removing a portion ofthe second type semiconductor layer and the light emitting layer throughetching, exposing a portion of the first type semiconductor layer,forming a metal layer ohm contacted with the first type semiconductorlayer, forming a second current limiting layer at the top region insidethe second type semiconductor layer, forming a transparent conductivelayer above the second type semiconductor layer and in ohm contact withthe second type semiconductor layer, wherein the transparent conductivelayer covers the second current limiting layer, removing a portion ofthe transparent conductive layer, exposing a portion of the second typesemiconductor layer, forming another metal layer directly in contactwith the second type semiconductor layer and electrically connected tothe transparent conductive layer, forming a first current blocking layercovering the sidewall region and the transparent conductive layer andremoving the epitaxial substrate. The first current blocking layer canreduce the non-radiative recombination of the magnetic micro-LED,thereby improving the efficiency of the magnetic micro-LED, wherein thefirst current blocking layer is composed of dielectric material. Thesecond current limiting layer can prevent the current crowding effectand improve the effect of current spreading, thereby increasing theprobability of electron-hole recombination, and light emittingefficiency can be improved, wherein the second current limiting layer isformed by ion implantation technique. The another metal layer isdirectly in contact with the second type semiconductor layer, whichgives the effect of stable bonding, and the stability of the structurecan be improved.

A lateral magnetic micro-LED structure is shown in FIG. 57-14. Thelateral magnetic micro-LED structure is formed by removing a portion ofthe second type semiconductor layer and the light emitting layer throughetching, exposing a portion of the first type semiconductor layer,forming a metal layer ohm contacted with the first type semiconductorlayer, forming a second current blocking layer above the second typesemiconductor layer, forming a transparent conductive layer above thesecond type semiconductor layer and in ohm contact with the second typesemiconductor layer, wherein the transparent conductive layer covers thesecond current blocking layer, removing a portion of the transparentconductive layer and the second current blocking layer, exposing aportion of the second type semiconductor layer, forming another metallayer directly in contact with the second type semiconductor layer andelectrically connected to the transparent conductive layer, forming afirst current limiting layer at the sidewall region and removing theepitaxial substrate. The first current limiting layer is located at thesurface and sidewall region of the magnetic micro-LED. The first currentlimiting layer can reduce the non-radiative recombination of themagnetic micro-LED, thereby improving the efficiency of the magneticmicro-LED, wherein the first current limiting layer is formed throughion implantation technique. The second current blocking layer canprevent the current crowding effect and improve the effect of currentspreading, thereby increasing the probability of electron-holerecombination, and light emitting efficiency can be improved, whereinthe second current blocking layer is composed of dielectric material.The another metal layer is directly in contact with the second typesemiconductor layer, which gives the effect of stable bonding, and thestability of the structure can be improved.

A vertical magnetic micro-LED structure is shown in FIG. 57-15, thevertical magnetic micro-LED structure is formed by forming a secondcurrent blocking layer above the second type semiconductor layer,forming a transparent conductive layer above the second typesemiconductor layer and in ohm contact with the second typesemiconductor layer, wherein the transparent conductive layer covers thesecond current blocking layer, removing a portion of the transparentconductive layer and the second current blocking layer, exposing aportion of the second type semiconductor layer forming a metal layerdirectly in contact with the second type semiconductor layer andelectrically connected to the transparent conductive layer, exposing thefirst type semiconductor layer by removing the epitaxial substrate and aportion of the magnetic layer, forming another metal layer ohm contactedwith the first type semiconductor layer and forming a first currentblocking layer covering the sidewall region and the transparentconductive layer. The first current blocking layer can reduce thenon-radiative recombination of the magnetic micro-LED, thereby improvingthe efficiency of the magnetic micro-LED, wherein the first currentblocking layer is formed through ion implantation technique. The secondcurrent blocking layer can prevent the current crowding effect andimprove the effect of current spreading, thereby increasing theprobability of electron-hole recombination, and light emittingefficiency can be improved, wherein the second current blocking layer iscomposed of dielectric material. The another metal layer is directly incontact with the second type semiconductor layer, which gives the effectof stable bonding, and the stability of the structure can be improved.

A vertical magnetic micro-LED structure is shown in FIG. 57-16, thevertical magnetic micro-LED structure is formed by forming a firstcurrent limiting layer at the sidewall region, forming a second currentlimiting layer at the top region inside the second type semiconductorlayer, forming a transparent conductive layer located above the secondtype semiconductor layer and in ohm contact with the second typesemiconductor layer, wherein the transparent conductive layer covers thesecond current limiting layer, removing a portion of the transparentconductive layer, exposing a portion of the second type semiconductorlayer, forming a metal layer directly in contact with the second typesemiconductor layer and electrically connected to the transparentconductive layer, forming a first current limiting layer at the sidewallregion, exposing the first type semiconductor layer by removing theepitaxial substrate and a portion of the magnetic layer and forminganother metal layer in ohm contact with the first type semiconductorlayer. The first current limiting layer is located at the surface andsidewall region of the magnetic micro-LED. The first current limitinglayer can reduce the non-radiative recombination of the magneticmicro-LED, thereby improving the efficiency of the magnetic micro-LED,wherein the first current limiting layer is formed through ionimplantation technique. The second current limiting layer can preventthe current crowding effect and improve the effect of current spreading,thereby increasing the probability of electron-hole recombination, andlight emitting efficiency can be improved, wherein the second currentlimiting layer is formed through ion implantation technique. The anothermetal layer is directly in contact with the second type semiconductorlayer, which gives the effect of stable bonding, and the stability ofthe structure can be improved.

A vertical magnetic micro-LED structure is shown in FIG. 57-17, thevertical magnetic micro-LED structure is formed by forming a secondcurrent limiting layer at the top region inside the second typesemiconductor layer, forming a transparent conductive layer above thesecond type semiconductor layer and in ohm contact with the second typesemiconductor layer, wherein the transparent conductive layer covers thesecond current limiting layer, removing a portion of the transparentconductive layer, exposing a portion of the second type semiconductorlayer, forming a metal layer directly in contact with the second typesemiconductor layer and electrically connected to the transparentconductive layer, forming a first current blocking layer covering thesidewall region and the transparent conductive layer, exposing the firsttype semiconductor layer by removing the epitaxial substrate and aportion of the magnetic layer and forming another metal layer in ohmcontact with the first type semiconductor layer.

The first current blocking layer can reduce the non-radiativerecombination of the magnetic micro-LED, thereby improving theefficiency of the magnetic micro-LED, wherein the first current blockinglayer is composed of dielectric material. The second current limitinglayer can prevent the current crowding effect and improve the effect ofcurrent spreading, thereby increasing the probability of electron-holerecombination, and light emitting efficiency can be improved, whereinthe second current limiting layer is formed through ion implantationtechnique. The another metal layer is directly in contact with thesecond type semiconductor layer, which gives the effect of stablebonding, and the stability of the structure can be improved.

A vertical magnetic micro-LED structure is shown in FIG. 57-18, thevertical magnetic micro-LED structure is formed by forming a firstcurrent limiting layer at the sidewall region, forming a second currentblocking layer above the second type semiconductor layer, forming atransparent conductive layer located above the second type semiconductorlayer and in ohm contact with the second type semiconductor layer,wherein the transparent conductive layer covers the second currentblocking layer, removing a portion of the transparent conductive layerand the second current blocking layer, exposing a portion of the secondtype semiconductor layer, forming a metal layer directly in contact withthe second type semiconductor layer and electrically connected to thetransparent conductive layer, exposing the first type semiconductorlayer by removing the epitaxial substrate and a portion of the magneticlayer and forming another metal layer in ohm contact with the first typesemiconductor layer. The first current limiting layer is located at thesurface and sidewall region of the magnetic micro-LED. The first currentlimiting layer can reduce the non-radiative recombination of themagnetic micro-LED, thereby improving the efficiency of the magneticmicro-LED, wherein the first current limiting layer is formed throughion implantation technique. The second current blocking layer canprevent the current crowding effect and improve the effect of currentspreading, thereby increasing the probability of electron-holerecombination, and light emitting efficiency can be improved, whereinthe second current blocking layer is composed of dielectric material.The another metal layer is directly in contact with the second typesemiconductor layer, which gives the effect of stable bonding, and thestability of the structure can be improved.

As shown in FIG. 57-19, because the magnetic micro-LED has a magneticlayer, the micro-LED with the magnetic layer can be massivelytransferred to a target substrate by controlling a transferring headwhich is magnetically attractive and controllable. Because the magneticforce of the magnetic layer shows good attraction to the transferringhead, yields of massive transfer can be improved.

As shown in FIG. 57-20, the magnetic micro-LED structure of the presentinvention is more suitable for fluid massive transfer. When the magneticmicro-LED is located in the fluid transfer system, because the magneticmicro-LED has a magnetic layer structure, the magnetic micro-LED canprovide self-alignment function through the magnetic layer, and theprobability of misalignment (for example, opposite polarity or wrongposition) happened during the fluid transfer can be reduced, therebyimproving the yields of massive transfer and reducing the cost.

A fluid transfer system including a main chamber is shown in FIG. 57-20.The main chamber includes a solution. A substrate is disposed in themain chamber, wherein the substrate has a plurality of recesses, thecentral of the recesses have a plurality of corresponding magneticlayers, the magnetic layer is located in the substrate, and a portion ofthe magnetic layer is exposed. The main chamber further includes aninput end, an input valve, an output end and an output valve. Bycontrolling the aperture ratio of the input valve and the output valve,the solution can form a fluid with a flow rate F. The fluid transfersystem includes a first sub-chamber, a second sub-chamber and a thirdsub-chamber, the first sub-chamber has a plurality of magneticmicro-LEDs with a first color, the solution, a first valve and a firstinput port. When the first valve is opened, the plurality of magneticmicro-LEDs with the first color can be moved downward through the firstvalve to a main chamber by the solution injected from the first inputport, and the magnetic micro-LEDs with the first color are respectivelymoved to the corresponding recess above the substrate by the fluid. Themagnetic micro-LEDs with the first color may be attracted by themagnetic force of the magnetic layer on the substrate and to move to therecess in a perform self-alignment manner, wherein the shape of therecess and the shape of the magnetic micro-LEDs with the first color arethe same. Accordingly, transfer of the magnetic micro-LEDs with thefirst color to the top of the substrate can be achieved.

The second sub-chamber has a plurality of magnetic micro-LEDs with asecond color, the solution, a second valve and a second input port. Whenthe second valve is opened, the plurality of magnetic micro-LEDs withthe second color can be moved downward through the second valve to amain chamber by the solution injected from the second input port, andthe magnetic micro-LEDs with the second color are respectively moved tothe corresponding recess above the substrate by the fluid. The magneticmicro-LEDs with the second color may be attracted by the magnetic forceof the magnetic layer on the substrate and move to the recess in aself-alignment manner, wherein the shape of the recess and the shape ofthe magnetic micro-LEDs with the second color are the same. Accordingly,transfer of the magnetic micro-LEDs with the second color to the top ofthe substrate can be achieved.

The third sub-chamber includes a plurality of magnetic micro-LEDs withthe third color, a solution, a third valve and a third input port. Whenthe third valve is opened, the plurality of magnetic micro-LEDs with thethird color can be moved downward through the third valve to a mainchamber by the solution injected from the third input port, and themagnetic micro-LEDs with the third color are respectively moved to thecorresponding recess above the substrate by the fluid. The magneticmicro-LEDs with the third color may be attracted by the magnetic forceof the magnetic layer on the substrate and to move to the recess in aself-alignment manner, wherein the shape of the recess and the shape ofthe magnetic micro-LEDs with the third color are the same. Accordingly,transfer of the magnetic micro-LEDs with the third color to the top ofthe substrate can be achieved.

FIG. 57-21-1 schematically illustrates a top view of the substrate ofthe fluid transfer system including a first recess with a first shape, asecond recess with a second shape and a third recess with a third shape,wherein each of the recesses has a magnetic layer, the shape of thefirst recess is the same as the shape of the magnetic micro-LEDs withthe first color, the shape of the second recess is the same as the shapeof the magnetic micro-LEDs with the second color, and the shape of thethird recess is the same as the shape of the magnetic micro-LEDs withthe third color.

When the first valve is opened, the plurality of magnetic micro-LEDswith the first color can be moved downward through the first valve to amain chamber by the solution injected from the first input port, and themagnetic micro-LEDs with the first color are respectively moved to thecorresponding recess above the substrate by the fluid. The magneticmicro-LEDs with the first color may be attracted by the magnetic forceof the magnetic layer on the substrate and move to the recess in aself-alignment manner, wherein the shape of the recess and the shape ofthe magnetic micro-LEDs with the first color are the same. Accordingly,transfer of the magnetic micro-LEDs with the first color to the top ofthe substrate can be achieved. The magnetic micro-LEDs with the firstcolor are located in the first recess above the substrate, and a firstsub-pixel area is thereby formed.

When the second valve is opened, the plurality of magnetic micro-LEDswith the second color can be moved downward through the second valve toa main chamber by the solution injected from the second input port, andthe magnetic micro-LEDs with the second color are respectively moved tothe corresponding recess above the substrate by the fluid. The magneticmicro-LEDs with the second color may be attracted by the magnetic forceof the magnetic layer on the substrate and move to the recess in aself-alignment manner, wherein the shape of the recess and the shape ofthe magnetic micro-LEDs with the second color are the same. Accordingly,transfer of the magnetic micro-LEDs with the second color to the top ofthe substrate can be achieved. The magnetic micro light emitting diodeswith the second color are located in the second recess above thesubstrate, and a second sub-pixel area is thereby formed.

When the third valve is opened, the plurality of magnetic micro-LEDswith the third color can be moved downward through the third valve to amain chamber by the solution injected from the third input port, and themagnetic micro-LEDs with the third color are respectively moved to thecorresponding recess above the substrate by the fluid. The magneticmicro-LED with the third color may be attracted by the magnetic force ofthe magnetic layer on the substrate and move to the recess in aself-alignment manner, wherein the shape of the recess and the shape ofthe magnetic micro-LEDs with the third color are the same. Accordingly,transfer of the magnetic micro-LEDs with the third color to the top ofthe substrate can be achieved. The magnetic micro-LEDs with the thirdcolor are located in the third recess above the substrate, and a thirdsub-pixel area is thereby formed.

The first sub-pixel area, the second sub-pixel area and the thirdsub-pixel area form a pixel area.

FIG. 57-21-2 schematically illustrates a top view of the substrate ofthe fluid transfer system including a first recess, a second recess anda third recess, wherein each of the recesses has a magnetic layer, andthe magnetic layer can be programmatic controlled. For example, themagnetic layer can be controlled to have magnetic attraction or have nomagnetic attraction by an electromagnetic force.

Before the first valve is opened, the magnetic layer in the first recesscan be controlled to have magnetic attraction, and the second valve andthe third valve are controlled to have no magnetic attraction. When thefirst valve is opened, the plurality of magnetic micro-LEDs with thefirst color can be moved downward through the first valve to a mainchamber by the solution injected from the first input port, and themagnetic micro-LEDs with the first color are respectively moved to thecorresponding recess above the substrate by the fluid. The magneticmicro-LEDs with the first color may be attracted by the magnetic forceof the magnetic layer on the substrate and move to the recess in aself-alignment manner. When the magnetic micro-LEDs are dropped into thesecond recess or the third recess, because the magnetic layers in thesecond recess and the third recess are controlled to have no magneticattraction, the magnetic micro-LEDs with the first color can be movedout from the second recess or the third recess until it is dropped intothe first recess by controlling the flow rate such that the thrust ofthe flow rate is greater than the capturing force of the second recessand the third recess. Accordingly, transfer of the magnetic micro-LEDswith the first color to the top of the substrate can be achieved,wherein the magnetic micro-LEDs with the first color are located in thefirst recess above the substrate, and a first sub-pixel area is therebyformed.

Before the second valve is opened, the magnetic layer in the firstrecess and the second recess can be controlled to have magneticattraction, and the third valve is controlled to have no magneticattraction. When the second valve is opened, the plurality of magneticmicro-LEDs with the second color can be moved downward through thesecond valve to a main chamber by the solution injected from the secondinput port, and the magnetic micro-LEDs with the second color arerespectively moved to the corresponding recess above the substrate bythe fluid. The magnetic micro-LEDs with the second color may beattracted by the magnetic force of the magnetic layer on the substrateand move to the recess in a self-alignment manner. When the magneticmicro-LEDs are dropped into the third recess, because the magneticlayers in the third recess are controlled to have no magneticattraction, the magnetic micro-LED with the second color can be movedout from the third recess until it is dropped into the second recess bycontrolling the flow rate such that the thrust of the flow rate isgreater than the capturing force of the third recess. Accordingly,transfer of the magnetic micro-LEDs with the second color to the top ofthe substrate can be achieved, wherein the magnetic micro-LEDs with thesecond color is located in the second recess above the substrate, and asecond sub-pixel area is thereby formed.

Before the third valve is opened, the magnetic layers of the firstrecess, the second recess and the third recess can be controlled to havemagnetic attraction. When the third valve is opened, the plurality ofmagnetic micro-LEDs with the third color can be moved downward throughthe third valve to a main chamber by the solution injected from thethird input port, and the magnetic micro-LEDs with the third color arerespectively moved to the corresponding recess above the substrate bythe fluid. The magnetic micro-LEDs with the third color may be attractedby the magnetic force of the magnetic layer on the substrate and move tothe recess in a self-alignment manner, thereby achieving the transfer ofthe magnetic micro-LEDs with the third color to the top of thesubstrate, wherein the magnetic micro-LEDs with the third color islocated in the third recess above the substrate, and a third sub-pixelarea is thereby formed.

The first sub-pixel area, the second sub-pixel area and the thirdsub-pixel area form a pixel area.

FIG. 57-22-1 and FIG. 57-22-2 schematically illustrates a top view ofthe substrate of the fluid transfer system including the first recess,the second recess and the third recess, wherein the substrate of thefluid transfer system further includes a first spare recess, a secondspare recess and a third spare recess, each of the recesses has amagnetic layer, each of the spare recesses has a spare magnetic layer,and the magnetic layer and the spare magnetic layer can be programmaticcontrolled. For example, the magnetic layer can be controlled to havemagnetic attraction or have no magnetic attraction by an electromagneticforce. When a test is performed after the magnetic micro-LEDs aretransferred, the position of the broken dot which is out of order isrecorded, and a massive repair is performed by the spare recesses. Themagnetic micro-LEDs are transferred to the corresponding spare recess toreplace the abnormal broken dot, and the repair can be completed.Because a large amount of the broken dots can be repaired at the sametime, time and cost for repairing can be drastically reduced. The shapeof each of the spare recesses can be similar to or different from theshape of the first recess, the second recess and the third recess. Thefirst recess and the first spare recess form a first sub-pixel area, thesecond recess and the second spare recess form a second sub-pixel area,the third recess and the third spare recess form a third sub-pixel area,wherein the first sub-pixel area, the second sub-pixel area and thethird sub-pixel area form a pixel area.

FIG. 57-23 schematically illustrates a fluid transfer system, whereinthe substrate of the fluid transfer system further includes a firstvalve of the substrate, a second valve of the substrate and a thirdvalve of the substrate. The valves of the substrate can be programmaticcontrolled. When the valve of the substrate is opened, the recess of thesubstrate is exposed, such that the substrate can capture the micro-LEDswhich are not limited to the magnetic micro-LEDs. The recess of thesubstrate further includes an attraction layer, wherein the attractionlayer can provide an electrical attraction force, a magnetic attractionforce, an electrostatic attraction force, a fluid attraction force, anair attraction force, a van der waals attraction force, a thermalattraction force and an attachment attraction force, and the producedattraction force can be used to capture the micro-LEDs in the fluid.

Before the first valve is opened, the first valve of the substrate iscontrolled to be opened, and the second valve of the substrate and thethird valve of the substrate are controlled to be closed. When the firstvalve is opened, the plurality of micro-LEDs with the first color can bemoved downward through the first valve to a main chamber by the solutioninjected from the first input port, and the micro-LEDs with the firstcolor are respectively moved to the corresponding recess above thesubstrate by the fluid. The micro-LEDs with the first color may beattracted by the attraction of the attraction layer on the substrate andmove to the recess in a self-alignment manner. Accordingly, transfer ofthe micro-LEDs with the first color to the top of the substrate can beachieved.

Before the second valve is opened, the second valve of the substrate iscontrolled to be opened, and the third valve of the substrate iscontrolled to be closed. When the second valve is opened, the pluralityof micro-LEDs with the second color can be moved downward through thesecond valve to a main chamber by the solution injected from the secondinput port, and the micro-LEDs with the second color are respectivelymoved to the corresponding recess above the substrate by the fluid. Themicro-LEDs with the second color may be attracted by the attraction ofthe attraction layer on the substrate and move to the recess in aself-alignment manner. Accordingly, transfer of the micro-LEDs with thesecond color to the top of the substrate can be achieved.

FIG. 57-24 schematically illustrates a fluid transfer system, whereinthe substrate of the fluid transfer system further includes anattraction layer which can be programmatic controlled. The attractionlayer can provide an electrical attraction force, a magnetic attractionforce, an electrostatic attraction force, a fluid attraction force, anair attraction force, a van der waals attraction force, a thermalattraction force and an attachment attraction force, and the producedattraction force can be used to capture the micro-LEDs in the fluid.

Before the first valve is opened, the first attraction layer of thesubstrate can be controlled to have attraction, and the secondattraction layer of the substrate and the third attraction layer of thesubstrate can be controlled to have no attraction. When the first valveis opened, the plurality of micro-LEDs with the first color can be moveddownward through the first valve to a main chamber by the solutioninjected from the first input port, and the micro-LEDs with the firstcolor are respectively moved to the corresponding recess above thesubstrate by the fluid. The micro-LEDs with the first color may beattracted by the attraction of the attraction layer on the substrate andmove to the recess in a self-alignment manner. When the micro-LEDs withthe first color is dropped into the second recess or the third recess,because the attraction layers in the second recess and the third recessare controlled to have no attraction, the micro-LEDs with the firstcolor can be moved out from the second recess or the third recess untilit is dropped into the first recess by controlling the flow rate suchthat the thrust of the flow rate is greater than the capturing force ofthe second recess and the third recess. Accordingly, transfer of themicro-LEDs with the first color to the top of the substrate can beachieved.

Before the second valve is opened, the first attraction layer of thesubstrate and the second attraction layer of the substrate can becontrolled to have attraction, and the third attraction layer of thesubstrate can be controlled to have no attraction. When the second valveis opened, the plurality of micro-LEDs with the second color can bemoved downward through the second valve to a main chamber by thesolution injected from the second input port, and the micro-LEDs withthe second color are respectively moved to the corresponding recessabove the substrate by the fluid. The micro-LEDs with the second colormay be attracted by the attraction of the attraction layer on thesubstrate and move to the recess in a self-alignment manner. When themicro-LEDs with the second color are dropped into the third recess,because the attraction layers in the third recess are controlled to haveno attraction, the micro-LEDs with the second color can be moved outfrom the third recess until it is dropped into the second recess bycontrolling the flow rate such that the thrust of the flow rate isgreater than the capturing force of the third recess. Accordingly,transfer of the micro-LEDs with the second color to the top of thesubstrate can be achieved.

Before the third valve is opened, the first attraction layer of thesubstrate, the second attraction layer of the substrate and the thirdattraction layer of the substrate can be controlled to have attraction.When the third valve is opened, the plurality of micro-LEDs with thethird color can be moved downward through the third valve to a mainchamber by the solution injected from the third input port, and themicro-LEDs with the third color are respectively moved to thecorresponding recess above the substrate by the fluid. The micro-LEDswith the third color may be attracted by the attraction of theattraction layer on the substrate and move to the recess in aself-alignment manner. Accordingly, transfer of the micro-LEDs with thethird color to the top of the substrate can be achieved.

FIG. 57-25 schematically illustrates a fluid transfer system, whereinthe substrate of the fluid transfer system further includes a fillinglayer, and the filling layer may be a photoresist, a dielectric layerwhich is heat dissolved or a solid which can be dissolved by the liquidin the chamber. When the filling layer is irradiated by a laser sourceor a UV light source, it would be dissolved and brought by the fluid,that is, the filling layer can be removed by irradiation or liquid flowby controlling the first valve of the substrate, the second valve of thesubstrate and the third valve of the substrate to be opened or closed,such that the programmatically controllable attraction layer below therecess can be exposed. The programmatically controllable attractionlayer and the attraction layer can provide an electrical attractionforce, a magnetic attraction force, an electrostatic attraction force, afluid attraction force, an air attraction force, a van der waalsattraction force, a thermal attraction force and an attachmentattraction force, and the produced attraction force can be used tocapture the micro-LEDs in the fluid.

The substrate of the present invention may be a flexible substrate,wherein the material of the flexible substrate may include ultra-thinglass, metal foil, fiber-reinforced composite material, plastic film,ceramic substrate or the combinations thereof. A preferable thickness ofthe flexible substrate is less than 200 micrometers, a more preferablethickness of the flexible substrate is less than 50 micrometers, and theeven more preferable thickness of the flexible substrate is in a rangefrom 25 micrometers to 50 micrometers. Metal foil may for exampleinclude stainless steel, nickel, titanium, zirconium, copper, iron,cobalt, palladium or the combinations thereof, wherein the coefficientof thermal expansion of metal foil is similar to the coefficient ofthermal expansion of ultra-thin glass. The surface roughness Ra of themetal foil is less than 10 nanometers. The light transmittance of theplastic film is greater than 90% under a wavelength of 550 nanometer.The material of the plastic film may for example include polyethyleneterephthalate (PET), polyethylene naphthalate (PEN) or polyethersulfone(PES).

Fiber-reinforced composite material may for example include carbonfibers, silicon carbide fibers or boron filament.

A Micro-LED device is provided by the present invention, and inparticular a Micro-LED device without spare design is provided. FIG.58-1A, FIG. 58-2A and FIG. 58-3A schematically illustrates a traditionaldisplay, wherein the horizontal resolution of the display is 960 pixels,the vertical resolution of the display is 640 pixels, the diagonaldistance of the display is 3.5 inches (8.89 centimeters (cm)), the sizeof the display is 2.91″×1.94″ which equals to 5.65 in² (7.4 cm×4.93cm=36.48 cm²) at 329.65 PPI, the dot pitch of the display is 0.0771 mm,and the resolution of the screen of the display is 960×640 (329.65 PPI).The resolution is sufficient to make it impossible for human eyes todistinguish single pixel, such as the Retina display which the lightemitting unit is for example a display equipment composed of threemicro-LEDs R, G and B. However, in the traditional device, when one ofthe micro-LEDs is out of order, it cannot be displayed and perceived byhuman eyes. The traditional method to solve this problem may for exampleinclude spare circuit design or spare micro-LEDs, but the cost can bethereby increased.

The present invention provides a Micro-LED device without spare design.FIG. 58-1B, FIG. 58-2B and FIG. 58-3B schematically illustrate anembodiment of the present invention, the horizontal resolution of thedisplay in this embodiment is 1920 pixels, the vertical resolution ofthe display is 1280 pixels, the diagonal distance of the display is 3.5inches (8.89 cm), the size of the display is 2.91″×1.94″ which equals to5.65 in² (7.4 cm×4.93 cm=36.48 cm²) at 659.3 PPI, the dot pitch of thedisplay is 0.0385 mm, and the resolution of the screen is1920×1280(659.3 PPI). An abnormal micro-LED between the two micro-LEDswith the same color is acceptable because that the abnormal micro-LED isnot easily perceived by human eyes, that is, the spare circuit design orthe spare micro-LED is not necessary. An abnormal pixel between the twopixels is acceptable because that the abnormal pixel is not easilyperceived by human eyes, that is, the spare circuit design or the sparemicro-LED is not necessary. An abnormal sub-pixel between the twosub-pixels with the same color is acceptable because that the abnormalsub-pixel is not easily perceived by human eyes, that is, the sparecircuit design or the spare micro-LED is not necessary.

The present invention provides a Micro-LED device without spare device.FIG. 58-1C, FIG. 58-2C and FIG. 58-3C schematically illustrate anotherembodiment of the present invention. The horizontal resolution of thedisplay in this embodiment is 3840 pixels, the vertical resolution ofthe display is 2560 pixels, the diagonal distance of the screen is 3.5inches (8.89 cm), the size of the display is 2.91″×1.94″ which equals to5.65 in² (7.4 cm×4.93 cm=36.48 cm²) at 1318.6 PPI, the dot pitch of thedisplay is 0.0193 mm, and the resolution of the screen of the display is3840×2560(1318.6 PPI). Two abnormal micro-LEDs between the twomicro-LEDs with the same color are acceptable because that the abnormalmicro-LEDs are not easily perceived by human eyes, that is, the sparecircuit design or the spare micro-LED is not necessary. Two abnormalpixels between the two pixels are acceptable because that the abnormalpixels are not easily perceived by human eyes, that is, the sparecircuit design or the spare micro-LED is not necessary. Two abnormalsub-pixels between the two sub-pixels with the same color are acceptablebecause that the abnormal sub-pixels are not easily perceived by humaneyes, that is, the spare circuit design or the spare micro-LED is notnecessary.

The present invention provides a Micro-LED device without spare design.In an embodiment, the horizontal resolution of the display in theembodiment is 1440 pixels, the vertical resolution of the display is 960pixels, the diagonal distance of the display is 3.5 inches (8.89 cm),the size of the display is 2.91″×1.94″ which equals to 5.65 in² (7.4cm×4.93 cm=36.48 cm²) at 494.48 PPI, the dot pitch of the display is0.0514 mm, and the resolution of the screen is 1440×960(494.48 PPI). Anabnormal micro-LED between the two micro-LEDs with the same color isacceptable because that the abnormal micro-LED is not easily perceivedby human eyes, that is, the spare circuit design or the spare micro-LEDis not necessary. An abnormal sub-pixel between the two sub-pixels isacceptable because that the abnormal sub-pixel is not easily perceivedby human eyes, that is, the spare circuit design or the spare micro-LEDis not necessary.

As shown in FIG. 58-1B, FIG. 58-1C, FIG. 58-2B, FIG. 58-2C, FIG. 58-3Band FIG. 58-3C, the micro-LEDs surrounded by the dotted line region areabnormal.

As shown in FIG. 58-1B, FIG. 58-1C, FIG. 58-2B, FIG. 58-2C, FIG. 58-3Band FIG. 58-3C, the sub-pixels surrounded by the dotted line region areabnormal.

The pixel of the present invention is composed of micro-LEDs with threedifferent colors (red, green and blue).

The pixel of the present invention is composed of sub-pixels with threedifferent colors (red, green and blue).

The dot pitch which describes the distance between the sub-pixels canalso be called as line pitch, stripe pitch, phosphor pitch or pixelpitch.

${P\; P\; I} = \frac{\sqrt{\left( {{\left\lbrack {{Horizontal}\mspace{14mu} {resolution}\mspace{14mu} ({pixel})} \right\rbrack^{\bigwedge}2} + {\left\lbrack {{Vertica1}\mspace{14mu} {resolution}\mspace{14mu} ({pixel})} \right\rbrack^{\bigwedge}2}} \right)}}{{Diagonal}\mspace{14mu} ({inch})}$

The normal formula for designing a Retina display is as follows:

a=2 arctan(h/2d)

As shown in FIG. 59, “a” is the viewing angle of human eyes, “h” is thedot pitch, and “d” is the distance between human eyes and screen. Thescreen fits the following requirements can make it impossible for humaneyes to see a single pixel, and can be called as Retina display.

h/2 = d × tan (a/2) a = 1/53.53  degreed = viewing  distance = 10  inches h = recognition  limith = 2 × d × tan   (1/53.53/2) × Π/180 if  d = 10  inch$\begin{matrix}{h = {2 \times 10 \times \tan \mspace{11mu} \left( {{1/53.53}/2} \right) \times {\Pi/1}80}} \\{= {0.003258911\mspace{14mu} {inch}}}\end{matrix}$ 1/h = 306.85  P P I if  d = 15  inch$\begin{matrix}{h = {2 \times 15 \times \tan \; \left( {{1/53.53}/2} \right) \times {\Pi/1}80}} \\{= {0.004888366831\mspace{14mu} {inch}}}\end{matrix}$ 1/h = 204.57  P P I if  d = 20  inch$\begin{matrix}{h = {2 \times 15 \times \tan \; \left( {{1/53.53}/2} \right) \times {\Pi/1}80}} \\{= {0.00651788224416\mspace{14mu} {inch}}}\end{matrix}$ 1/h = 153.42  P P I

pixels distance per inch between of dot dot dot dot screen eyes andretina pitch pitch pitch pitch size screen display (× 1) (× 1.5) (× 2)(× 4) (inch) (inch) (PPI) (mm) (mm) (mm) (mm) 1-7 10 306.85 0.082770.05518 0.041388 0.020694 6601 4401  3  15  7-12 15 204.57 0.124160.08277 0.062081 0.031040 2878 5252 439  72 12-30 20 153.42 0.165550.11037 0.082779 0.041389 8597 2398 299 649

The resolution is increased and the distance between the sub-pixels isreduced to make it impossible for human eyes to perceive the abnormalsub-pixel in the present invention, that is, the Micro-LED device withspare design is not necessary. Take an embodiment of the presentinvention shown in the table above for example, the table shown abovelists different screen size and the suitable distance between human eyesand screen for each case. That is, PPI and dot pitch of the Retinadisplay which makes it impossible for human eyes to see a single pixelcan be calculated. The human eyes cannot easily perceive the abnormalsub-pixel by shrinking the dot pitch to 1/1.5, ½ and ¼ of the originaldot pitch, such that the Micro-LED device with spare design is notnecessary.

The resolution is increased and the distance between the sub-pixels isreduced to make it impossible for human eyes to perceive the abnormalsub-pixel in an embodiment of the present invention, and the device cancombined with the Micro-LED device with spare design to adapt to theapplication with greater resolution.

FIG. 60A is a schematic cross-section view of a light emitting diodestructure 4000 according to an embodiment. Referring to FIG. 60A, thelight emitting diode structure 4000 includes a stack of layers which atleast having a first type semiconductor layer 4001, a second typesemiconductor layer 4002, an light emitting layer 4003 interposedbetween the first type semiconductor layer 4001 and the second typesemiconductor layer 4002, a first electrode layer 4000 n disposed on asurface of the first type semiconductor layer 4001, a second electrodelayer 4000 p disposed on a surface of the second type semiconductorlayer 4002, and structural regions 4000 sr covering at least a portionof the first type semiconductor layer 4001, the light emitting layer4003 and the second type semiconductor layer 4002.

As the embodiment shown in the FIG. 60A, the light emitting diodestructure 4000 is a lateral LED structure of which the first electrodelayer 4000 n and the second electrode layer 4000 p are disposed at thesame side of the first type semiconductor layer 4001, but the inventionis not limited thereto.

In the embodiment of the FIG. 60A, the structural regions 4000 sr mayinclude current blocking regions, but not limited thereto. In oneembodiment, the structural regions 4000 sr. In one embodiment, thestructural regions 4000 sr may include current limiting regions.

In an embodiment, the structural regions 4000 sr may include dielectriclayer or layers. Material of the dielectric layer or layers may be, butnot limited thereto, silicon oxide (SiO₂), silicon nitride (Si₃N₄),aluminum oxide (Al₂O₃), yttrium oxide (Y₂O₃), titanium oxide (TiO₂),hafnium oxide (HfO₂), zirconium oxide (ZrO₂), barium zirconate (BaZrO₃),barium titanate (BaTiO₃), tantalum pentoxide (Ta₂O₅) and Silica, etc. Inan embodiment, the dielectric layer or layers may be passivationlayer(s). In an embodiment, the dielectric layers may be opticalmultilayer thin films which are interlaced higher dielectric index filmsand lower dielectric index films. In an embodiment, the opticalmultilayer thin films may perform as a reflecting mirror according tothe wavelength of the light emitting diode.

In an embodiment, the first type semiconductor layer 4001, the secondtype semiconductor layer 4002 and/or the light emitting layer 4003 maybe multi-layered, but the invention is not limited thereto.

Further referring to the embodiment of FIG. 60A, a length L of the lightemitting diode structure 4000 may not be greater than 100 micrometers.In the embodiment of the FIG. 60A, the light emitting diode structure4000 includes a light outputting surface 4000 sl and a bonding surface4000 sb. The surface 4000 sb of the light emitting diode structure 4000may be a planar surface with roughness not greater than 10 nanometers(nm). The surface 4000 sb may be composited with surfaces of thedielectric layer 4000 sr, the first electrode layer 4000 n and/or thesecond electrode layer 4000 p. In the embodiment of FIG. 60A, thesurface 4000 sb of the light emitting diode structure 4000 may beapplied as a boning surface for attaching to a circuit substrate.

FIG. 60B is a schematic cross-section view of a light emitting diodestructure 4000′ according to another embodiment which is similar to FIG.60A. Referring to the embodiment of FIG. 60B, the structural regions4000 sr may cover the side surface of the light emitting diode structure4000′ and extend from the surface 4000 sb to the light outputtingsurface 4000 sl.

FIG. 60C is a schematic cross-section view of a light emitting diodestructure 4000″ according to an embodiment. Referring to the embodimentof FIG. 60C, a width w42 of the first electrode layer 4000 n near thesurface 4000 sb may be wider than a width w41 of the first electrodelayer 4000 n near the first type semiconductor layer 4001. In theembodiment, the wider portion w42 of the first electrode layer 4000 nmay perform as a reflecting mirror to reflect the light emitted from thelight emitting layer 4003, and then the outputting intensity of thelight from the light outputting surface 4000 sl may be enhanced. Inanother embodiment, the second electrode layer 4000 p may also have awider portion near the surface 4000 sb and the wider portion of thesecond electrode layer 4000 p may perform as a reflecting mirror.

FIG. 60D is a schematic cross-section view of a light emitting device4000D according to an embodiment. Referring to the embodiment of FIG.60D, the light emitting device 4000D includes a plurality of lightemitting diode elements 4000 arranged in an array and the arrayed lightemitting diode elements 4000 are sandwiched between a first substrate4000 w 1 and a second substrate 4000 w 2.

In the embodiment of FIG. 60D, the first substrate 4000 w 1 may be acarrier substrate and the second substrate 4000 w 2 may be a circuitsubstrate, but the invention is not limited thereto. The secondsubstrate (circuit substrate) 4000 w 2 may include driver circuits, suchas thin-film transistor (TFT) drivers. The plurality of light emittingdiode elements 4000 may be transferred and array placed to the firstsubstrate 4000 w 1, and then electrode pads of the arrayed lightemitting diode elements 4000 are respectively bonded to contact pads ofthe driver circuits through the bonding surface 4000 sb of the arrayedlight emitting diode elements 4000 and a bonding surface 4000 sb′ of thesecond substrate 4000 w 2.

In the embodiment of FIG. 60D, the surface 4000 sb of each lightemitting diode element 4000 may be a planar surface with roughness notgreater than 10 nm. Referring back to the embodiment of FIG. 60A, thesurface 4000 sb may be composited with surfaces of the dielectric layer4000 sr, the first electrode layer 4000 n and/or the second electrodelayer 4000 p. In other words, at least portion surfaces of thedielectric layer 4000 sr, the first electrode layer 4000 n and/or thesecond electrode layer 4000 p are coplanar. Accordingly, the bondingsurface 4000 sb′ of the second substrate (circuit substrate) 4000 w 2may be a planar surface including surfaces of contact pads of the drivercircuits. In the embodiment of FIG. 60D, bonding interfaces of thesurfaces 4000 sb and 4000 sb′ may include dielectric layer, such assilicon oxide layer, and copper layer, but the invention is not limitedthereto. The bonding surface 4000 sb can be directly bonded to thebonding surface 4000 sb at a lower temperature which may be not greaterthan 150° C., therefore thermal stress induced by coefficient of thermalexpansion (CTE) mismatch can be decreased and open contacts between theelectrodes of the light emitting diode elements 4000 and the contactpads of the driver circuits can be prevented.

The structural description of the word “coplanar” should be understoodto allow for typical variations that occur during the semiconductormanufacturing, such as from dishing from planarization, from subsequentcleaning processes, etc.

In one embodiment, the first substrate 4000 w 1 may be an epitaxysubstrate or a growing substrate of the arrayed light emitting diodeelements 4000. The first substrate 4000 w 1 may be light-transmittableaccording to the wavelength of the light emitted from the light emittinglayer 4003. In one embodiment, the first substrate 4000 w 1 may beremoved or thinned after the bonding process.

In another embodiment, the second substrate 4000 w 2 may be a circuitsubstrate and also perform as a carrier substrate, each light emittingdiode element 4000 is transferred to the second substrate 4000 w 1 andthen electrode pads of each light emitting diode element 4000 are bondedto contact pads of the driver circuits through the bonding surface 4000sb of the light emitting diode element 4000 and the bonding surface 4000sb′ of the second substrate 4000 w 2.

In the embodiment of FIG. 60D, gaps between the light emitting diodeelements 4000 may be filled with sealing materials 4000 f. In oneembodiment, the sealing materials 4000 f may include light-absorbermaterials to prevent light crosstalk between adjacent light emittingdiode elements, and the light-absorber materials may be polymer filledwith black or dark particles, but the invention is not limited thereto.In one embodiment, the sealing materials 4000 f may include inorganicinsulting materials such as silicon oxide, silicon nitride. In anotherembodiment, the structural regions 4000 sr at side surfaces of eachlight emitting diode elements 4000 may perform as passivation layer(s),therefore the sealing materials 4000 f may include heat conductingparticles, such as metal particles, ceramic particles, and thepassivation layer(s) can prevent short circuits induced by the metalparticles between adjacent light emitting diode elements.

FIG. 60E-1 is a top view of a light emitting device 4000E′ according toan embodiment and FIG. 60E-2 is a schematic cross-section view of thelight emitting device 4000E. Referring to the embodiment of FIG. 60E-1,the wavelength conversion layer 4000 ps includes windows F, F1, F2 andF3 in matrix form and a matrix frame FM surrounding the windows F, F1,F2 and F3. The matrix frame FM may be not light transmissive or mayabsorb light, but the invention is not limited thereto.

In the embodiment of FIG. 60E-1, the windows F, F1, F2 and F3 is lighttransmissive and phosphors included in the windows F, F1, F2 and F3 maybe different from each other, so that colors of light radiated from thewindows F, F1, F2 and F3 may be different from each other. For example,phosphors included in the windows F1 may be excited by light of theunderneath light emitting diode elements 4000 and radiate red light,phosphors included in the windows F2 may be excited by light of theunderneath light emitting diode elements 4000 and radiate yellow light,phosphors included in the windows F3 may be excited by light of theunderneath light emitting diode elements 4000 and radiate green light,but the invention is not limited thereto. In one embodiment, one or moretypes of phosphors may be included in one window.

The amount of the light emitting diode elements 4000 below each one ofthe window F, F1, F2 and F3 may be one or more, and the amount of thelight emitting diode elements 4000 below at least two of the window F,F1, F2 and F3 may be different from each other.

When the amount of the light emitting diode elements 4000, below onecommon window, is more than one and each of the light emitting diodeelements 4000 can be individually controlled, the brightness of thelight radiated from the common window can be tuned by switching anamount of the light emitting diode elements 4000 which is turned on. Forexample, referring to the window region F1 shown in FIG. 60E-1,brightest red light is radiated from the window F1 when all the sixunderneath light emitting diode elements 4000 are turned on and darkestred light is radiated from the window F1 when only one underneath lightemitting diode element 4000 is turned on.

Referring to the embodiment of FIG. 60E-2, there are plural of lightemitting diode elements 4000 arranged in an array under the window F3 ofthe light emitting device 4000E′ and a wavelength conversion layer 4000ps that covers the light emitting element array. In the embodiment ofFIG. 60E-2, the wavelength conversion layer 4000 ps, for example,contains a light transmissive resin and phosphors, but the invention isnot limited thereto. The matrix frame FM, which surrounds the window F3,may be a light non-transmissive wall structure for preventing lightcross-talk to adjacent regions such as the adjacent windows F and F2.

In an embodiment, the wavelength conversion layer 4000 ps may includelight scattering particles therein. The light, entering the wavelengthconversion layer 4000 ps, can be scattered by the light scatteringparticles for many times so as to fully interact with the phosphorsinside the wavelength conversion layer 4000 ps and uniformly radiate outfrom the wavelength conversion layer 4000 ps.

Referring to the embodiment of FIG. 60E-2, under the common window F3,the filling material 4000 f′ filled between adjacent light emittingdiode elements 4000, for example, may further include the aforementionedlight transmissive resin, phosphors and/or light scattering particles,but the invention is not limited thereto.

The phosphors may include cerium-activated yttrium aluminum garnet-basedphosphors (YAG:Ce); cerium-activated lutetium aluminum garnet-basedphosphors (LAG:Ce); europium-activated and/or chromium-activatednitrogen-containing calcium aluminosilicate-based phosphors (forexample, CaO—Al₂O₃—SiO₂:Eu); europium-activated silicate-based phosphors((Sr,Ba)₂SiO₄:Eu); nitride-based phosphors, such as β-SiAlON phosphors,CASN-based phosphors (CaAlSiN₃:Eu), SCASN-based phosphors((Sr,Ca)AlSiN₃:Eu); KSF-based phosphors (K₂SiF₆:Mn); sulfide-basephosphors, and/or quantum dot phosphors, but the invention is notlimited thereto. In an embodiment, through combining these phosphorswith a blue or ultraviolet light emitting element, various colors oflight (e.g., a white light emitting device) can be produced by the lightemitting device.

The phosphors, for example, may include a blue phosphor, a greenphosphor, a yellow phosphor, a red phosphor, or quantum dots (QDs). Forexample, blue phosphors may include BAM-based, halo-phosphate-based, oraluminate-based phosphors, and may include, for example,BaMgAl₁₀O₁₇:Mn²⁺,BaMgAl₁₂O₁₉:Mn²⁺ or (Sr,Ca,Ba)PO₄Cl:Eu²⁺.

Green or yellow phosphors may include LuAG(Lu₃(Al,Gd)₅O₁₂:Ce³⁺),YAG(Y₃(Al,Gd)₅O₁₂:Ce³⁺), Ga-LuAG((Lu,Ga)₃(Al,Gd)₅O₁₂:Ce³⁺),Ga-YAG((Ga,Y)₃(Al,Gd)₅O₁₂:Ce³⁺), LuYAG((Lu,Y)₃(Al,Gd)₅O₁₂:Ce³⁺),((Sr,Ba,Ca,Mg)₂SiO₄:Eu²⁺), ((Ba,Sr,Ca)Si₂O₂N₂:Eu²⁺) or thio-gallate(SrGa₂S₄:Eu²⁺).

Red phosphors may include nitride, sulfide, fluoride, or oxynitride, andmore specifically, CASN(CaAlSiN₃:Eu²⁺), (Ba,Sr,Ca)₂Si₅N₈:Eu²⁺, (Ca,Sr)S₂:Eu²⁺) or (Sr,Ca)₂SiS₄:Eu²⁺.

Quantum dots (QDs) may include Si, Ge, GaN, GaP, GaAs, GaSb, AlN, AlP,AlAs, AlSb, InN, InP, InAs, InSb, SnS, SnSe, SnTe, PbS, PbSe, PbTe, CdO,CdS, CdSe, CdTe, ZnO, ZnS, ZnSe, ZnTe, HgS, HgSe, HgTe, MgSe, MgS, SiC,SiGe, GaNP, GaNAs, GaNSb, GaPAs, GaPSb, AlNP, AlNAs, AlNSb, AlPAs,AlPSb, InNP, InNAs, InNSb, InPAs, InPSb, SnSeS, SnSeTe, SnSTe, PbSeS,PbSeTe, PbSTe, SnPbS, SnPbSe, SnPbTe, GaAlNP, GaAlNAs, GaAlNSb, GaAlPAs,GaAlPSb, GaInNP, GaInNAs, GaInNSb, GaInPAs, GaInPSb, InAlNP, InAlNAs,InAlNSb, InAlPAs, InAlPSb, CdSeS, CdSeTe, CdSTe, ZnSeS, ZnSeTe, ZnSTe,HgSeS, HgSeTe, HgSTe, CdZnS, CdZnSe, CdZnTe, CdHgS, CdHgSe, CdHgTe,HgZnS, HgZnSe, HgZnTe, MgZnSe, MgZnS, CdZnSeS, CdZnSeTe, CdZnSTe,CdHgSeS, CdHgSeTe, CdHgSTe, HgZnSeS, HgZnSeTe, HgZnSTe, SnPbSSe,SnPbSeTe, SnPbSTe, Graphene quantum dots (GQDs) and/or mixtures thereof.For example, a spectrum distribution of a light transferred from thequantum dots may having a full width at half maximum (FWHM) from 10 nmto 60 nm in a wavelength band of green light. For example, a spectrumdistribution of a light transferred from the quantum dots may having afull width at half maximum (FWHM) from 30 nm to 80 nm in a wavelengthband of red light. For example, a spectrum distribution of a lighttransferred from the quantum dots may having a full width at halfmaximum (FWHM) lower than 60 nm for wide color gamut application.

The wavelength conversion member may comprise at least one of epoxyresin, silicones, polystyrene resin and acrylate.

FIG. 60E-3 is an enlarged top view of a window region F′ of a lightemitting device according to an embodiment. Referring to the embodimentof FIG. 60E-3, the six light emitting diode elements 4000 can becategorized into two groups Ua and Ub, and the three light emittingdiode elements Ub are provided as backups for the three light emittingdiode elements Ua. In a normal operation, light from the window regionF′ is mainly provided by the three light emitting diode elements Ua andthe three light emitting diode elements Ub are kept in off status ordisabled. When a light emitting diode element Ua is broken, a controlleror a switch circuit, coupled to the broken light emitting diode elementUa, disables the broken light emitting diode element Ua and enables anadjacent light emitting diode element Ub for replacing the broken lightemitting diode element Ua.

In the embodiments of FIGS. 60F-60K, the structural regions 4000 sr mayhave an arc corner. By controlling the geometric shape of the structuralregions 4000 sr, a preferred effect of reducing sidewall leakage currentcan be achieved and the light emitting efficiency of the micro lightemitting diode can be improved. When the pitch of light emitting diodeelements is reduced, the arc corner can effectively avoid ElectrostaticDischarge (ESD) caused by the point discharge, corona discharge orelectrical breakdown of the light emitting diode elements, and thenimprove the production yield rate.

In addition, the production yield of mass transfer can be improved byshaping the corner of the Micro-LEDs in arc shape. In one embodiment,for the electrostatic transfer process, crack or damages induced bycollisions between the sharp corner of the Micro-LEDs and the electroniccomponents on the transferred circuit substrate can be effectivelyavoid. In one embodiment, for the micro transfer printing process, thearc corner shape of the Micro-LED can effectively solve the toleranceissue of the mounting surfaces. In one embodiment, for the fluidtransfer process, crack induced by collisions between the Micro-LEDs canbe effectively avoid.

Further referring to the embodiment shown in FIG. 60K, the productionyield of the redistribution layers 4000RDL can be improved bycontrolling the geometric shape of the structural regions 4000 sr. Inthe embodiment, the arc corner at the structural region 4000 sr of theMicro-LED can effectively prevent disconnect redistribution layers4000RDL, and the arc corner at the structural region 4000 sr also canimprove the flexibility of arranging the redistribution layers 4000RDL.

The above-mentioned embodiments are not intended to limit the scope ofthe present invention. Those skilled in the art should realize thecontents of the present invention can be modified, combined or displacedaccording to the demands of design and other factors. Any modification,replacement and improvement according to the spirit and principle of thepresent invention should be included in the scope of the presentinvention.

What is claimed is:
 1. A diode array, comprising: a substrate; and aplurality of light emitting diodes disposed on the substrate andarranged in an array, wherein each of the light emitting diodes includesa stack of functional layers comprising a first type semiconductorlayer, a second type semiconductor layer, and a light emitting layerlocated between the first type semiconductor layer and the second typesemiconductor layer, wherein at least one of the light emitting diodesincludes: a first current limiting region abutting a verticallyextending boundary of the second semiconductor layer; wherein, withrespect to a top down view, the first current limiting region is formedabout an outer edge of the light emitting diode and an outer perimeterof the first current limiting region is equal to or less than 400micrometers (μm).
 2. The light emitting diode of claim 1, wherein thefirst current limiting region further comprises a first upper surfaceextending in a first direction, a first outer surface extending in asecond direction, and a first inner boundary extending in a thirddirection, wherein the first direction and the second directionintersect at a first angle, the first direction and the third directionintersect at a second angle, and at least one of the first angle and thesecond angle is substantially perpendicular.
 3. The light emitting diodeof claim 1, wherein the first current limiting region further comprisesa first outer surface, wherein the second type semiconductor layerfurther comprises a second outer surface, and either a roughness of thefirst outer surface is greater than 10 nanometers or a roughness of thesecond outer surface is greater than 10 nanometers (nm).
 4. The diodearray of claim 1, further comprising: a wall structure located betweenadjacent light emitting diodes.
 5. The light emitting diode of claim 1,wherein further comprising an arc corner about the outer edge of thelight emitting diode.
 6. The light emitting diode of claim 1, whereinthe first current limiting region and the second semiconductor layer areformed of the same semiconductor layer, and the first current limitingregion further comprises a first upper surface, the second typesemiconductor layer comprises a second upper surface, and the secondupper surface and the first upper surface are coplanar.
 7. The lightemitting diode of claim 1, wherein the first current limiting regioncomprises a first upper surface in a first region of the samesemiconductor layer, and the second semiconductor layer comprises asecond upper surface in a second region of the same semiconductor layerand adjacent to the first upper surface, wherein a conductivity of thesame semiconductor layer at the first upper surface and the second uppersurface increases with respect to a direction from the first region tothe second region.
 8. The light emitting diode of claim 1, wherein thefirst current limiting region comprises a first upper surface having afirst conductivity, and the second semiconductor layer comprises asecond upper surface having a second conductivity higher than the firstconductivity; wherein the first upper surface has a first surfaceroughness no greater than 10 nanometers (nm).
 9. The light emittingdiode of claim 1, wherein the first current limiting region furthercomprises a first upper surface, and the second type semiconductor layerfurther comprises a second upper surface, wherein the first uppersurface has a first surface roughness, the second upper surface has asecond surface roughness, and the first surface roughness is greaterthan or equal to the second surface roughness.
 10. The light emittingdiode of claim 1, further comprising a second current limiting region,wherein a shortest distance between the first current limiting regionand the second current limiting region is equal to or less than 50micrometers (μm).
 11. The light emitting diode of claim 10, furthercomprising a third current limiting region located between the firstcurrent limiting region and the second current limiting region, whereinan upper surface of the third current limiting region and an uppersurface of the first current limiting region are coplanar.
 12. The lightemitting diode of claim 10, wherein bottoms of the first currentlimiting region and the second current limiting region are formed at thesame depth.
 13. The light emitting diode of claim 1, wherein the stackof functional layers further comprises a sidewall region and an uppersurface region, wherein the sidewall region, which is covered with thefirst current limiting region, has a first thickness; and the uppersurface region, which is covered with the first current limiting region,has a second thickness, wherein the first thickness is greater than orequal to the second thickness.
 14. The diode array of claim 1, furthercomprising: a wavelength conversion material covers at least one of thelight emitting diodes, wherein a first wavelength of light radiated fromthe wavelength conversion material is different from a second wavelengthof light radiated from the at least one of the light emitting elements.15. The diode array of claim 1, wherein a first group of the pluralityof light emitting diodes radiate a first color of light; and a secondgroup of the plurality of light emitting diodes radiate a second colorof light; wherein the first color is different from the second color,and at least one of the second group of the light emitting diodes islocated between the adjacent ones of the first group of the lightemitting diodes.
 16. The diode array of claim 1, further comprising: acircuit integrally formed with the substrate electrically connected tothe array of the plurality of light emitting diodes; and a plurality ofmicrocontroller chips in communication with corresponding ones of thelight emitting diodes for providing a scan driving signals or a datadriving signals to the array of the plurality of light emitting diodesthrough the circuit.
 17. A display device, comprising: at least one ofthe diode array of claim 16 for providing an image light; an opticalcomponent for receiving the image light from the diode array andtransporting the image light to a viewer; and a control system forcontrolling the image light.
 18. The display device of claim 17, whereinthe optical component corresponds to a transmissive windshield glass, atransparent resin glass, a transmissive eyeglasses lens or a foldabledisplay which has light transmission or reflection function.
 19. Thedisplay device of claim 17, further comprising a sensor for receiving ansignal from the viewer and transmitting the instruction signal to thecontrol system.
 20. A method for fabricating a display device, themethod comprising: providing a diode array of claim 15 for providing animage light; providing an optical component for receiving the imagelight radiated from the diode array and transporting the image light toa viewer; and providing a control system for controlling the image lightradiated from the diode array through the microcontroller chips.